International
Tables for
Crystallography
Volume C
Mathematical, physical and chemical tables
Edited by E. Prince

International Tables for Crystallography (2006). Vol. C, ch. 9.6, pp. 818-883

Table 9.6.3.3 

A. G. Orpen,a L. Brammer,b F. H. Allen,c D. G. Watsonc and R. Taylorc

aSchool of Chemistry, University of Bristol, Bristol BS8 1TS, England,bDepartment of Chemistry, University of Missouri–St Louis, 8001 Natural Bridge Road, St Louis, MO 63121-4499, USA, and cCambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, England

Table 9.6.3.3| top | pdf |
Interatomic distances (Å)

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
1.1.1.1 Hydrides (terminal) 27
Fe—H all BASLIQ10 1.609 1.610 0.004 1.605 1.612 6  
Zn—H see MAEMAZ11 (1.617)              
Mo—H see HCYPMO02 (1.684)              
Rh—H see CONFEQ01 (1.578, 1.583)              
Ta—H see TACPTH (1.769, 1.774, 1.776)              
W—H all IPPHWH01 1.732 1.734 0.010 1.725 1.740 6  
Re—H (8), (-) 1.684 1.681 0.015 1.676 1.697 12  
Os—H all THMPOS01 1.659 1.656 0.017 1.646 1.677 4  
Ir—H all DETSOK 1.603 1.607 0.021 1.582 1.623 5  
Pt—H see CAKNEH01 (1.610)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
1.1.1.2 Hydrides (μ2-H) 27
Cr—H see KCPTCR01 (1.725, 1.723)              
Fe—H all HMYCFE01 1.670 1.670 0.001 1.669 1.672 4  
Mo—H (6, 7), (II, III) 1.842 1.843 0.023 1.819 1.864 4  
Ru—H (), (-) 1.782 1.776 0.019 1.773 1.791 22  
Rh—H (4, ), (I) 1.775 1.768 0.040 1.738 1.811 8  
W—H (6), (0) 1.900 1.897 0.028 1.876 1.926 5  
Re—H (8, ), (I, IV) 1.832 1.832 0.039 1.793 1.870 16  
Os—H (), (-) 1.817 1.824 0.029 1.798 1.837 34  
Ir—H see CUSGAY (1.821, 1.847)              
Pt—H see CAKNEH01 (range 1.656–2.049)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
1.1.1.3 Hydrides (μ3-H) 27
Co—H see HMPCIC01 (1.728, 1.731, 1.742)              
Ni—H all TCPNIH11 1.691 1.684 0.022 1.673 1.715 9  
Rh—H see HMPCRH11 (1.847, 1.855, 1.873)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
1.2.1.1 BH4 [M—(μ2-H)—B] 28
Cu—H see TMPCUB01 (1.698)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
1.2.1.2 BH4 [M—(μ2-H)2—BH2]  
Co—H see BEGBIY01 (1.707, 1.740)              
Th—H see MCHFHB10 (2.069, 2.120)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
2.1.1 Borohydrides [M(—H—)BH2R] 28
Sc—B see BOVCAQ (2.528)              
Ti—B see CPCLBT (2.178)              
Cr—B see BOSKUP (2.294)              
Co—B (-), (I): (η2-BH4, μ21, η1′-BH4) 2.218 2.224 0.030 2.199 2.241 6  
Ni—B see YBAENI (3.088)              
Cu—B see BOLJAN (2.441), CICFID (2.204, 2.232), PHRLCU (2.079), TMPCUB01 (2.517)              
Zn—B see CAPFOO (2.219), NBCZNB10 (2.252, 2.253)              
Y—B see BUWBAW (2.478, 2.836), HBTHFY (2.574, 2.680)              
Zr—B see CANFAY (2.335)              
Mo—B see HBMPMO (2.468)              
Ru—B see CIZBOC (2.237)              
Os—B see COCKOU (2.300)              
U—B (-), (III, IV): all 2.569 2.510 0.136 2.494 2.644 16  
  (-), (IV): [(μ-H)3BR] 2.493 2.498 0.040 2.459 2.515 11  

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
2.2.1 Boranes/carbaboranes (not H-bridged) (see also 3.21.1) 29
Ti—B see CEXTII (2.355, 2.375, 2.383)              
V—B see BUPLAZ10 (2.246, 2.322, 2.333)              
Cr—B   2.228 2.252 0.054 2.178 2.266 9  
Mn—B   2.255 2.231 0.058 2.213 2.306 9  
Fe—B   2.140 2.135 0.066 2.103 2.179 111  
Co—B   2.086 2.082 0.073 2.036 2.124 270  
Ni—B   2.106 2.108 0.049 2.071 2.142 41  
Cu—B see BOTPCU (2.209, 2.237), TPCUBF (2.273)              
Ru—B :all 2.263 2.234 0.167 2.041 2.377 16 30
  :short < 2.10 2.035 2.033 0.012 2.026 2.046 5  
  :long > 2.25 2.367 2.355 0.067 2.318 2.399 11  
Rh—B   2.224 2.219 0.061 2.188 2.252 55  
Pd—B   2.237 2.244 0.041 2.197 2.260 10  
Ag—B see TPACUB (2.352, 2.420, 2.522)              
W—B   2.403 2.393 0.036 2.381 2.416 7  
Re—B   2.292 2.287 0.056 2.239 2.349 6  
Os—B see BUVROZ (2.147, 2.184, 2.283)              
Ir—B   2.236 2.205 0.083 2.183 2.287 29  
Pt—B   2.243 2.244 0.062 2.213 2.283 94  
Au—B   2.238 2.228 0.034 2.206 2.256 11  
Hg—B see COBHGA (2.201, 2.286), TPMCDB10 (2.204, 2.498, 2.521)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
2.2.2 Boranes/carbaboranes [M(—H—)B] (hydrogen located) 29
Mn—B   2.228 2.222 0.025 2.208 2.254 4  
Fe—B see TPCUBF (2.115)              
Co—B   2.100 2.086 0.032 2.079 2.125 15  
Cu—B see TPCUBF (2.164)              
Zn—B see CEXSAZ (2.264, 2.274)              
Ru—B see COKTIF (2.327, 2.462)              
Rh—B   2.342 2.330 0.040 2.311 2.384 4  
W—B see COVROU (2.413)              
Ir—B see BELJEH (2.290, 2.281), CTPIRB (2.250), TPICBO (2.452, 2.480)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
2.3.1 Boracycles (see also 3.21.2 and 4.23.1) 31–33
V—B see BOKXEE (2.369)              
Cr—B excluding BRNOCR (2.566) 2.340 2.349 0.026 2.312 2.360 7  
Mn—B   2.291 2.282 0.047 2.252 2.299 7  
Fe—B   2.227 2.185 0.097 2.163 2.279 13  
Co—B   2.123 2.097 0.076 2.073 2.189 12  
Ni—B see CIDBOG (2.411), CPBORN (2.175), FMBCNI (2.260), SIBONI (2.226), VIBONI (2.500, 2.550)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.1.1.1 Carbide (μ4-C) 34, 35
Hg—C see FAHGME (2.042)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.1.1.2 Carbide (μ5-C) 34, 35
Ru—C   2.049 2.043 0.057 2.004 2.084 40  
Os—C   2.060 2.056 0.059 2.004 2.108 35  

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.1.1.3 Carbide (μ6-C) 34, 35
Ru—C   2.060 2.063 0.023 2.040 2.076 60  
Rh—C see CBACRC (2.122, 2.132, 2.125)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.2.1.1 Carbyne/alkylidyne (terminal CR, R = any C) 36, 37
C—C   1.468 1.475 0.031 1.436 1.495 18  
Cr—C (6), (-) 1.702 1.710 0.029 1.679 1.720 5 38
Mo—C see BENFEF (1.799)              
Ta—C see BESPIY (1.850), TABYCP10 (1.849)              
W—C (5, 6), (IV, VI) 1.815 1.821 0.041 1.777 1.840 9  
Re—C see CECROR (1.742)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.2.1.2 Carbynes/alkylidynes (μ2-CR, R = any C, H) 39
C—C   1.480 1.478 0.030 1.452 1.510 4  
Ru—C see VCPRUB10 (1.933, 1.941), CIFXOE (1.936)              
W—C   1.955 1.947 0.021 1.940 1.973 6  

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.2.1.3 Carbynes/alkylidynes (μ3-CR, R = any C, H)    
C—C   1.510 1.505 0.025 1.494 1.526 21  
Fe—C   1.928 1.933 0.024 1.910 1.939 15  
Co—C   1.896 1.895 0.035 1.874 1.920 27  
Mo—C   2.059 2.056 0.019 2.042 2.075 11  
Ru—C   2.084 2.089 0.027 2.067 2.102 6  
Rh—C all R = H 1.964 1.970 0.020 1.945 1.980 7  
Os—C all COTPOQ01 2.101 2.102 0.004 2.097 2.105 6  

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.2.2.1 Amino carbynes (terminal CNR2)    
(M)C—N   1.322 1.334 0.053 1.271 1.368 5  
N—C   1.469 1.470 0.027 1.441 1.485 8  
Cr—C see BAMCOH (1.750), SNCOCR (1.743)              
Mo—C see BITKIY (1.797)              
W—C see CAVREW (1.776, 1.747)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.2.3.1 Thiocarbynes (terminal CSR)    
C—S (1.712, 1.713)              
Mo—C see CAWSAU (1.801)              
W—C see TPCPTW (1.810)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.3.1.1 Vinylidenes/alkenylidenes (terminal CCR2) 40
C=C   1.318 1.312 0.032 1.295 1.329 7  
Fe—C see COPMID (1.780, 1.799)              
Mo—C see BUJFIV (1.918), CVMOMP10 (1.833)              
Ru—C see BOJJUF (1.845)              
Rh—C see CAYMAQ (1.820)              
W—C see CEFVUE (1.983)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.3.1.2 Vinylidenes/alkenylidenes (μ2-CCR2)  
C=C   1.317 1.315 0.023 1.305 1.326 7  
Mn—C see EYCCMN (1.971, 1.978)              
Fe—C see CHPECI (1.969, 1.955)              
Co—C   1.885 1.885 0.021 1.864 1.904 4  
Ru—C see VCPRUA10 (2.025, 2.034)              
Rh—C see BECVOU (1.987, 1.989)              
Os—C see BEXJUJ (2.096, 2.102)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.4.1.1 Acetylides/alkynyls (terminal CCR)  
C[triple bond]C   1.188 1.188 0.017 1.178 1.202 16  
C—C   1.456 1.451 0.030 1.436 1.465 16  
V—C see CIJLUC (2.074)              
Fe—C see CPFPEY (1.920)              
Rh—C see BIMTEW (1.939)              
Pd—C see EYPIPD (1.953)              
W—C see BONSUS (2.134)              
Ir—C see CEFPEI (2.041)              
Pt—C (4, 6), (II, IV) 1.992 2.000 0.032 1.985 2.009 8 41
Hg—C see PEYHGP (2.047, 2.031)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.4.1.2 Acetylides/alkynyls (μ2-CCR)§ 42
C—C   1.231 1.232 0.026 1.206 1.256 4  
Fe—Cσ see ACYPCI (1.890)              
—Cπ (2.117, 2.283)              
Ru—Cσ see BAYCOS (2.047), BOBTOB (2.044)              
—Cπ see BAYCOS (2.323, 2.423); BOBTOB (2.285, 2.508)              
Pt—Cσ see MSIPEP (1.964)              
—Cπ see MSIPEP (2.141, 2.468)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.5.1.1 Cyano (terminal CN) 43
C—N   1.146 1.146 0.014 1.138 1.154 168  
V—C see CIRSAX (2.067), CIRSEB (2.088)              
Cr—C (6), (-): all 2.058 2.063 0.024 2.031 2.080 8 7
Mn—C see CAZJAO10 (1.996, 1.989)              
Fe—C (5, 6), (0, II, III): all 1.937 1.935 0.023 1.923 1.950 33  
Co—C (5, 6), (-): all 1.896 1.900 0.019 1.883 1.907 50 8
Ni—C (4, 5), (-): all 1.883 1.868 0.076 1.852 1.873 30  
  excluding 2 > 2.1 1.864 1.868 0.021 1.851 1.872 28  
Cu—C (3, 5), (-): all 2.003 1.975 0.101 1.924 2.098 5 12
Zn—C (4), (-): all 2.000 1.997 0.012 1.991 2.013 4  
Mo—C (6, 7, 8), (-): all 2.167 2.166 0.021 2.155 2.184 21 15, 44
Ru—C see BEPJIP (2.025)              
Pd—C see BEJHUT (1.997)              
Ag—C see COLSEB (2.093)              
Pt—C (4, 5), (II): all 1.943 1.931 0.031 1.916 1.977 5  
Au—C see CIGCOK (2.003)              
Hg—C see BINRAR (2.187, 2.174), CAHRUY (2.100)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.5.1.2 Cyano (μ2-CN)§ (see also 4.4.2)  
C—N   1.143 1.147 0.016 1.132 1.153 21  
Cr—C see CYCRTF (1.999, 1.972, 1.965)              
Mn—C see CAZJAO10 (1.995)              
Fe—C (6), (III) 1.948 1.942 0.025 1.928 1.972 6  
Ni—C (4), (II) 1.859 1.853 0.017 1.847 1.877 4  
Cu—C (4), (I) 1.951 1.965 0.030 1.914 1.974 6 12
Pd—C see BUSRIQ (2.011)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.6.1.1 Isocyanides (terminal CNR, R = any C) 45, 46
C—N   1.149 1.147 0.016 1.139 1.157 220  
V—C see CIRSAX (2.003), CLBCNV (2.189)              
Cr—C (6, 7), (0–III): R = Ph, tBu, Bz 1.996 2.003 0.038 1.969 2.014 21 7
Mn—C (6), (-): R = Ph, tBu, Me 1.927 1.924 0.028 1.900 1.947 15  
Fe—C (5, 6, ), (0–II): all 1.862 1.867 0.048 1.819 1.901 12  
  (6), (II): all 1.874 1.874 0.043 1.832 1.901 7  
Co—C see BISJOC (1.851, 1.846, 1.866)              
Ni—C (3, 4), (0): R = tBu 1.853 1.854 0.021 1.838 1.870 6  
Cu—C (3, 4), (I): R = tBu, p-Tol, cyh 1.896 1.895 0.009 1.890 1.905 7  
Nb—C (7, 8), (-): R = tBu 2.241 2.237 0.036 2.208 2.270 6  
Mo—C (5–8), (0–IV) 2.107 2.115 0.040 2.089 2.135 61 15
  (5–8), (II) 2.111 2.115 0.032 2.094 2.131 56  
  (5–7), (II): R = tBu 2.108 2.115 0.030 2.089 2.125 36  
Ru—C (6, ), (-) 1.986 1.997 0.040 1.941 2.014 7  
Rh—C (4–6), (-) 1.968 1.969 0.036 1.955 1.983 21  
  (4), (-) 1.956 1.962 0.031 1.947 1.975 13  
Pd—C (3–5), (-) 1.985 1.974 0.036 1.958 2.020 18 47
  (4), (-) 1.978 1.972 0.035 1.955 1.994 15  
Ag—C see BUXGAC (2.162, 2.136)              
Pr—C see CXINPR10 (2.654)              
W—C (7), (II): R = tBu 2.102 2.105 0.035 2.070 2.125 11  
Re—C (6, 7), (I–II) 2.002 2.008 0.022 1.980 2.018 12  
Os—C see CIRJAO (1.983, 2.004), HOSTBC10 (2.032)              
Ir—C see MCPEIR (1.945), MICPIR10 (1.986)              
Pt—C (4, 5, ), (-) 1.936 1.924 0.059 1.896 1.968 13  
  (4, 5), (-) 1.944 1.966 0.036 1.912 1.968 7  

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.6.1.2 Isocyanides (μ2-CNR)  
C—N   1.221 1.227 0.038 1.196 1.241 15  
Fe—C   1.941 1.941 0.025 1.920 1.948 12  
Ni—C all MINCNI 1.881 1.880 0.022 1.861 1.903 4  
Os—C see HYBIOS (2.072, 2.039)              
Pt—C all BIDCAS 2.100 2.086 0.070 2.038 2.170 12  

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.7.1.1 Carbon monoxide (terminal CO) 48
C—O   1.145 1.143 0.020 1.132 1.156 10022  
Ti—C   2.003 1.997 0.030 1.980 2.030 5 49
V—C   1.946 1.946 0.037 1.924 1.974 60  
Cr—C   1.866 1.867 0.037 1.835 1.895 925 38
Mn—C   1.808 1.805 0.034 1.784 1.833 789  
Fe—C   1.782 1.784 0.030 1.765 1.801 2572 50
Co—C   1.780 1.781 0.034 1.758 1.801 662  
Ni—C   1.771 1.776 0.029 1.750 1.794 34 51
Cu—C   1.787 1.782 0.019 1.776 1.807 18 12
Zr—C see CCPZRA (2.187)             49
Nb—C   2.073 2.073 0.028 2.056 2.092 26  
Mo—C   1.978 1.973 0.041 1.947 2.007 748 15
Tc—C   1.884 1.883 0.021 1.866 1.904 4 17
Ru—C   1.896 1.896 0.036 1.873 1.919 1453  
Rh—C   1.847 1.846 0.040 1.821 1.869 238  
Ta—C see BISZIM (2.036), BUVGII (2.083), CPMPTA (2.008)              
W—C   2.002 2.007 0.043 1.971 2.034 508 24
Re—C   1.936 1.933 0.050 1.898 1.978 370  
Os—C   1.902 1.903 0.036 1.880 1.927 1443  
Ir—C   1.870 1.876 0.042 1.839 1.898 148  
Pt—C   1.853 1.854 0.056 1.821 1.878 29  

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.7.1.2 Carbon monoxide (μ2-CO) 52
C—O   1.171 1.171 0.022 1.159 1.183 279  
Mn—C (all) 1.940 1.930 0.021 1.926 1.955 8  
  (M—C—M < 70°) 1.929 1.928 0.005 1.924 1.933 6  
Fe—C (all) 1.941 1.925 0.041 1.914 1.971 104  
  (M—C—M < 80°) 1.985 1.995 0.037 1.953 2.018 20  
  (80° < M—C—M < 86°) 1.930 1.921 0.034 1.908 1.946 80  
Co—C   1.914 1.919 0.046 1.883 1.947 114  
Ni—C   1.882 1.880 0.021 1.870 1.892 14  
Cu—C   1.861 1.862 0.015 1.854 1.872 6  
Mo—C (all) 2.127 2.091 0.095 2.045 2.237 6  
  (Mo=Mo only) 2.068 2.064 0.027 2.045 2.095 4  
Ru—C (all) 2.072 2.055 0.047 2.038 2.099 66  
  (non-clusters) 2.040 2.039 0.021 2.026 2.055 20  
  (clusters) 2.086 2.087 0.048 2.043 2.114 46  
Rh—C (all) 2.040 2.037 0.055 1.994 2.076 180  
  (M—C—M < 85°) 2.057 2.058 0.059 2.000 2.111 106  
  (85° < M—C—M < 95°) 2.018 2.029 0.037 1.984 2.046 68  
  (M—C—M > 115°) 1.983 1.982 0.007 1.977 1.990 4  
Pd—C (all) 2.004 1.997 0.039 1.979 2.015 14  
Re—C (all BAWTOI) 2.073 2.072 0.009 2.063 2.080 6  
Os—C   2.081 2.063 0.057 2.042 2.122 6  
Ir—C   2.065 2.072 0.039 2.026 2.093 30  
Pt—C   2.044 2.039 0.032 2.018 2.063 6  

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.7.1.3 Carbon monoxide (μ3-CO) 42
C—O   1.190 1.191 0.038 1.173 1.202 33  
Fe—C   2.002 1.990 0.037 1.980 1.997 15  
Co—C   1.950 1.949 0.032 1.937 1.962 15  
Ni—C see TCPDNI01 (1.931, 1.932)              
Ru—C   2.171 2.169 0.020 2.153 2.193 8  
Rh—C see POSHRH10 (2.205, 2.155, 2.238)              
Pd—C see BUJYIO (2.190, 2.078, 2.157)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.8.1.1 CS (terminal)  
C—S   1.563 1.570 0.030 1.536 1.587 5  
Cr—C see BUGRIE (1.778), MBZCRC (1.797), TLCSCR (1.751)              
Mn—C see ICPNMN (1.803)              
Fe—C see BEPDEF (1.662)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.8.1.2 CS (μ2-CS)  
C—S (1.597, 1.606, 1.618)              
Fe—C all CPTCFF 1.886 1.889 0.007 1.878 1.891 4  

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.9.1.1 Carbene/alkylidene (terminal CH2) 36
Re—C see CAHZUG (1.898)              
Os—C see CAMTEP (1.924)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.9.1.2 Carbenes/alkylidenes (μ2-CR2, R = any C, H) 39, 53
Mn—C see BANGIG10 (2.026), MYCCMN10 (2.018, 2.019)              
Fe—C   2.006 1.990 0.045 1.974 2.052 6  
Co—C   1.934 1.925 0.025 1.909 1.961 7  
Ru—C   2.085 2.095 0.056 2.076 2.112 12  
Rh—C   2.048 2.059 0.033 2.017 2.075 15  
W—C excluding BIJJAF (2.127, 2.436) 2.298 2.296 0.035 2.266 2.331 4  
Re—C all CEHFEA 2.141 2.132 0.030 2.119 2.171 4  
Os—C excluding CODCON (1.922, 1.909) 2.160 2.155 0.041 2.136 2.192 20  
Au—C   2.112 2.102 0.026 2.095 2.139 4  

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.9.2.1 Carbenes/alkylidenes (terminal CHR)  
C—C   1.490 1.493 0.027 1.462 1.513 14  
Ta—C (5, 6, 8), (V): all 1.963 1.938 0.065 1.932 2.030 7 54, 55
W—C (5–7), (IV, VI) 1.953 1.942 0.086 1.871 2.041 5 38, 55
Re—C see BOBYAS (1.949), CECROR (1.873)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.9.3.1 Carbenes/alkylidenes (terminal CR2)  
C—C [R = C (sp3)] 1.503 1.509 0.024 1.500 1.519 12  
Mn—C see CERJIS (1.853), MCBCMN (1.864, 1.871)              
Fe—C see CPCFEA10 (1.978)              
W—C see DPCBWC (2.132, 2.154)             38, 55
Ir—C see PYBPIR (1.998)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.9.4.1 Alkoxy carbenes [terminal CR(OR), R = any C]  
(M)C—O   1.318 1.314 0.023 1.300 1.338 18  
(M)C—C   1.501 1.503 0.032 1.479 1.524 18  
O—C   1.466 1.459 0.024 1.452 1.484 18  
Cr—C (6), (-) 2.012 2.006 0.029 1.988 2.039 5 38, 55
Mn—C see BOCWAR (1.848), MNXCMN (1.890), NPMCMN (1.950)             55
Co—C see PGECBC (1.912)              
Mo—C see BEBTUX (2.087)              
W—C (6), (-) 2.161 2.161 0.014 2.148 2.175 4  
Re—C see CMNCBR (2.098)              
Os—C see BODGUW10 (1.981)              
Pt—C see CIPTMN (1.889), EOBCPT10 (1.920)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.10.1.1 Vinyls (σ-CRCR2)§ 41
C=C   1.345 1.344 0.024 1.333 1.357 98  
Ti—C (8), (IV) 2.215 2.239 0.042 2.171 2.243 7  
Cr—C all MPEYCR10 2.035 2.033 0.009 2.027 2.045 4  
Mn—C see BIZJEZ (1.985), CECCIW (2.009), MASBCM (2.027)              
Fe—C (5, 6), (II) 1.991 1.997 0.039 1.954 2.030 10  
Co—C (6), (-) 1.934 1.932 0.019 1.914 1.946 8  
Ni—C (4, 5), (-) 1.892 1.900 0.017 1.874 1.903 4  
Zr—C see CPPHZR (2.249, 2.265)              
Mo—C (7), (-) 2.204 2.223 0.049 2.151 2.247 5  
Ru—C see CNBRUB (2.073), CXFMPR (2.082), PCFMRU10 (2.034)              
Rh—C   2.040 2.060 0.054 1.986 2.085 5  
Pd—C (4), (II) 2.000 2.006 0.024 1.989 2.011 16 47
Hf—C see CPTPHF (2.190, 2.219)              
W—C see BEDGAS (2.202), COPMEZ (2.275), MCTCEW (2.194)              
Os—C see CIRNOG (2.052)              
Ir—C (5, 6), (-) 2.071 2.073 0.044 2.036 2.103 6  
Pt—C (4,5), (-) 2.024 2.022 0.037 1.991 2.058 17 41
Au—C see BULPED (2.039, 2.045)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.10.1.2 Vinyls (η2-CRCR2)§  
Cα—Cβ   1.408 1.407 0.013 1.418 1.442 8  
Mo—Cα   1.936 1.937 0.020 1.917 1.954 4  
—Cβ   2.292 2.293 0.027 2.265 2.316 4  
W—Cα   1.918 1.907 0.030 1.898 1.949 4  
—Cβ   2.251 2.249 0.078 2.181 2.324 4  

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.10.1.3 Vinyls (μ21, η2-CRCR2)§ 39
Cα—Cβ   1.408 1.407 0.022 1.395 1.421 43  
Mn1—Cα see BOWYOB (2.058, 2.053)              
Mn2—Cα see BOWYOB (2.086, 2.102)              
—Cβ see BOWYOB (2.263, 2.263)              
Fel—Cα   1.996 2.004 0.036 2.000 2.009 8  
Fe2—Cα   2.102 2.095 0.039 2.079 2.111 8  
Fe2—Cβ   2.219 2.197 0.046 2.183 2.260 8  
Co1—Cα see BOCCOC (1.973, 1.968), BULYOW (1.981)              
Co2—Cα see BOCCOC (2.009, 2.011), BULYOW (1.995)              
—Cβ see BOCCOC (2.132, 2.115), BULYOW (2.127)              
Mo1—Cα see BEDDAP (2.151, 2.140), CAMKIK (2.141)              
Mo2—Cα see BEDDAP (2.181, 2.181), CAMKIK (2.232)              
—Cβ see BEDDAP (2.301, 2.301), CAMKIK (2.446)              
Ru1—Cα   2.079 2.075 0.043 2.060 2.089 13  
Ru2—Cα   2.221 2.227 0.057 2.191 2.260 13  
—Cβ   2.276 2.276 0.042 2.247 2.284 13  
Rh1—Cα see BATNIT (2.045), FMPENR (2.025, 2.028)              
Rh2—Cα see BATNIT (2.100), FMPENR (2.058, 2.102)              
—Cβ see BATNIT (2.222), FMPENR (2.139, 2.205)              
W1—Cα (6, 7), (0, II, IV): all 2.158 2.145 0.043 2.128 2.203 6  
W2—Cα (6), (IV): excluding 2.266, 2.124 2.412 2.412 0.034 2.380 2.445 4  
—Cβ (6), (II, IV): excluding 1 at 2.220 2.458 2.470 0.047 2.410 2.500 5  
Re1—Cα see COTFAS (2.170, 2.098)              
Re2—Cα see COTFAS (2.359, 2.255)              
—Cβ see COTFAS (2.352, 2.307)              
Os21Cα see CHVINO (2.108), HPETOS (2.154), UCHXOS (2.170)              
Os2—Cα see CHVINO (2.273), HPETOS (2.151), UCHXOS (2.188)              
—Cβ see CHVINO (2.362), HPETOS (2.300), UCHXOS (2.311)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.11.1.1 σ-Aryls (η1-Ar)§  
Cl—C2   1.396 1.396 0.021 1.381 1.409 398  
C2—C3   1.393 1.392 0.022 1.379 1.406 398  
C3—C4   1.378 1.379 0.025 1.364 1.395 399  
Ti—C see PFPBTI (2.135), PSIBTI (2.161)              
V—C (4, 6), (II, III) 2.114 2.115 0.012 2.102 2.124 4  
Cr—C (5, 6), (II, III) 2.075 2.072 0.019 2.061 2.089 10 38
Mn—C (6), (I) 2.064 2.059 0.021 2.044 2.083 6  
Fe—C (4, 6), (I, II) 2.031 2.022 0.062 1.985 2.065 6  
  (6), (I, II) 2.008 2.021 0.021 1.974 2.030 5  
Co—C see DMDECO01 (1.995), ETPSCO10 (1.997), TOPFCO10 (1.931)              
Ni—C (4, 5), (II, III) 1.917 1.929 0.038 1.893 1.942 18  
Cu—C see CODJIO (2.020)              
Mo—C (4, 5, 7), (0, II, IV): all 2.193 2.176 0.054 2.164 2.195 11 38
  (4, 5), (II, IV) 2.172 2.169 0.016 2.160 2.187 9  
Ru—C (5, 6), (II) 2.092 2.121 0.057 2.013 2.136 7  
Rh—C (5, 6), (II, III) 2.011 2.000 0.026 1.990 2.037 9  
Pd—C (4, ), (II): all 1.981 1.987 0.032 1.965 2.002 28 47
Lu—C see CILCUV (2.425, 2.427, 2.455)              
Ta—C (5), (V) 2.199 2.173 0.073 2.147 2.276 4  
Re—C see PHTPRE (2.024, 2.029)              
Os—C (6, ), (-) 2.090 2.092 0.032 2.058 2.120 4  
Ir—C (4–6, ), (I, III): all 2.070 2.067 0.038 2.043 2.092 17  
  (6), (III) 2.053 2.049 0.024 2.037 2.071 10  
Pt—C (4–6), (I, II, IV): all 2.049 2.061 0.046 2.033 2.079 35 41
  (4), (I, II) 2.055 2.062 0.039 2.043 2.079 28  
Au—C (2–4, ), (I, III): all 2.059 2.062 0.024 2.052 2.073 22  
  (2, 3), (I) 2.053 2.050 0.009 2.045 2.062 5  
  (4), (III) 2.062 2.068 0.031 2.055 2.081 13  
Hg—C (2–4, ), (II): all 2.086 2.088 0.040 2.054 2.120 24  
  (2, 3), (II) 2.053 2.057 0.027 2.040 2.075 12  
  (), (-): all BIPHHG 2.120 2.119 0.014 2.115 2.126 12  

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.12.1.1 Acyls [η1-C(O)R]§  
C=O   1.210 1.209 0.023 1.195 1.218 60  
Mn—C see PNMNCP (2.012), PYRMNC (2.076)              
Fe—C (6), (II) 1.997 2.004 0.033 1.967 2.028 18  
Co—C see BOBSUG (1.915), OXCOCP10 (2.055)              
Ni—C (4, 5), (II) 1.850 1.870 0.059 1.788 1.893 4  
Mo—C see BOLCIO10 (2.049), MABUMO10 (2.168)              
Ru—C see BEWMAR (2.091)              
Rh—C (5, 6), (III): all 1.995 1.996 0.031 1.969 2.006 10  
Pd—C (4), (II): all 1.982 1.992 0.029 1.951 2.002 4  
Re—C (6), (I) 2.190 2.183 0.027 2.175 2.214 7  
Os—C see BUYMAJ (2.161)              
Ir—C see NRBIRB (1.971), POIRID (2.067)              
Pt—C (4), (II) 1.991 2.000 0.025 1.969 2.008 7  

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.12.1.2 Acyls [η2-C(O)R]§ (see also 5.25.1)  
C=O   1.240 1.238 0.014 1.227 1.248 10  
Zr—C see BOPSII (2.181, 2.186)              
Mo—C   2.014 2.020 0.011 2.003 2.023 6  
W—C see BUSYIX (2.030), COSSOS (2.000)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.13.1.1 Methyl (terminal CH3)  
Ti—C see BASMOX (1.969), INDMTI (2.206)              
Cr—C see CAMVER (2.168)              
Mn—C (6), (IV): all CAJHOK 2.095 2.105 0.030 2.068 2.124 4  
Fe—C see BNTLFE (2.080), CEDMON (2.065), CMZTFE (2.077)             50
Co—C (6), (III) 2.014 2.014 0.023 1.993 2.032 16  
Ni—C see BAPKEI (2.035), PEAMNI (2.023)             56
Zr—C IV, (4–6, 8) 2.292 2.279 0.049 2.257 2.346 8  
Nb—C see CPSNBA (2.346), CPSNBB (2.327)             54
Mo—C (5–7), (II–IV, VI): all 2.254 2.282 0.065 2.189 2.296 15  
Ru—C (5, 6), (II) 2.179 2.156 0.045 2.143 2.226 5  
Rh—C (5, 6), (II, III) 2.092 2.101 0.027 2.064 2.113 4  
Hf—C (8), (IV) 2.275 2.267 0.049 2.233 2.325 4  
Ta—C (6, 7), (III, V) 2.217 2.215 0.035 2.181 2.247 7 54
W—C (4–6), (II, III, VI) 2.189 2.187 0.039 2.166 2.213 13  
Re—C (5, 6), (I, III) 2.173 2.188 0.051 2.123 2.201 8  
Ir—C see BEJBEX (2.218), CODPIR10 (2.133)              
Pt—C (4–6), (II, IV): all 2.083 2.077 0.045 2.047 2.117 58 41
  (4, 5), (II) 2.107 2.115 0.044 2.069 2.136 30  
  (6), (IV) 2.057 2.056 0.028 2.038 2.077 28  
Au—C (4), (III) 2.066 2.045 0.045 2.030 2.118 18 57
Hg—C (2–4), (II) 2.072 2.071 0.026 2.056 2.092 29  
Th—C see COSZOZ (2.567)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.13.2.1 Primary alkyls [CH2R, R = C(sp3)]  
C—C   1.521 1.528 0.033 1.512 1.540 90  
Ti—C see BILWIC (2.138, 2.152), BOYZOE (2.210)              
Mn—C (4, 6), (I, II) 2.176 2.173 0.024 2.154 2.199 5  
Fe—C (6), (II) 2.091 2.082 0.030 2.071 2.102 8  
Co—C (6), (II, III) 2.039 2.037 0.032 2.018 2.061 14  
Ni—C see ACTPEN (1.970), BENIIB (1.973), DIPNIP (1.948)             56
Zn—C see PMCZNE (1.964)              
Nb—C see CPETNB (2.316), ONBCBU (2.322)             54
Mo—C (4–8), (II–IV, VI): all 2.250 2.252 0.061 2.208 2.272 12  
  (4–8), (III, IV, VI) 2.230 2.234 0.042 2.195 2.269 10  
Ru—C (4), (III): all CIBGEZ 2.036 2.033 0.010 2.029 2.045 6  
Rh—C see CIDJEE (2.094), PBUDRI10 (2.098, 2.107)              
Pd—C see BIHLOT01 (2.051), HIMPDA (2.009, 2.023)              
Ta—C (5, 7), (V) 2.225 2.208 0.056 2.183 2.289 6 54
W—C see COPXIO (2.141, 2.126), DMPMPW10 (2.257)              
Re—C see COMPRH (2.285), ETDYRE (2.296)              
Os—C see BOTTAF (2.220, 2.219), BUYNEO (2.203)              
Pt—C (4–6), (II, IV) 2.062 2.065 0.031 2.039 2.085 14 41
Hg—C see CIRMAR (2.125)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.13.3.1 Primary alkyl [CH2R, R = C(sp2)]  
C—C   1.477 1.478 0.028 1.464 1.496 108  
Ti—C see CEYCOY (2.203, 2.204)              
Cr—C see BELTUH (2.101)              
Mn—C see ACPMNA (2.209), BUFLET (2.199), CABYUZ (2.127)              
Fe—C (5, 6), (0, II) 2.131 2.133 0.038 2.098 2.155 9  
Co—C (5, 6), (-) 2.061 2.085 0.061 2.001 2.109 5  
Ni—C see IPRNIP (1.977)             56
Zn—C see CLPDZN (2.030)              
Zr—C (8), (IV) 2.320 2.306 0.034 2.298 2.355 4  
Nb—C (8), (IV, V) 2.289 2.291 0.024 2.271 2.306 14 54
Mo—C (4–6), (II, III, VI) 2.211 2.214 0.027 2.187 2.233 9  
Ru—C see CALHIG (2.200)              
Rh—C see CIHYOH (2.103)              
Pd—C (4, 5, ), (II, -) 2.050 2.044 0.042 2.019 2.071 20  
Hf—C see CEYCUE (2.274, 2.284)              
Ta—C see CBZYTA (2.304), CPBZTB (2.188, 2.233)             54
W—C (5–8), (II, III, V): all 2.238 2.185 0.090 2.163 2.328 9  
Re—C see BUVSOA (2.203), BZHREC (2.284)              
Os—C see BUYMAJ (2.217)              
Ir—C see BIYJIC (2.127), CIYKAW (2.167), POIRID (2.133)              
Pt—C (4, 5), (II) 2.067 2.081 0.033 2.032 2.089 4 41
Hg—C see CHGACA (2.107), DBEZHG (2.064)              
Th—C all CEKGEE 2.554 2.555 0.022 2.535 2.570 7  
U—C (6, 10), (IV) 2.509 2.521 0.039 2.468 2.539 4  

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.13.4.1 Secondary alkyls [terminal CHR2, R = C(sp3)]  
C—C   1.532 1.534 0.033 1.510 1.554 72  
Fe—C see BULLFE (2.168), CAGKEA (2.060), MEDOFE10 (2.079)              
Co—C (6), (III) 2.086 2.090 0.028 2.058 2.111 4  
Ni—C see CONBIQ (1.929)             56
Zr—C see CALNUY (2.381)              
Ru—C (5, 6), (II) 2.145 2.153 0.032 2.112 2.171 4  
Rh—C see HBUPRH (2.083)              
Pd—C (4, 5), (II) 2.035 2.041 0.036 2.003 2.051 9  
Ir—C (5, 6), (III) 2.107 2.107 0.035 2.074 2.141 7  
Pt—C (4, 5), (II) 2.078 2.073 0.038 2.046 2.116 4 41
Hg—C see CHGALD (2.085)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.13.5.1 Secondary alkyls {CHR2, R2 ≠ [C(sp3)2]}  
C—C R = C(sp2) 1.474 1.475 0.023 1.461 1.485 82  
  R = C(sp3) 1.532 1.527 0.022 1.518 1.545 40  
Ti—C see TCYPTI10 (2.332)              
Fe—C (5, 6), (-) 2.131 2.138 0.027 2.110 2.151 16  
Co—C (6), (-) 2.075 2.086 0.029 2.052 2.093 5  
Zr—C see PDPMZR10 (2.379, 2.396)              
Mo—C see BIRLIX (2.405)              
Ru—C see BDMFRU (2.180), CTERUC (2.138)              
Rh—C see BIGHAA (2.192), CASDIJ (2.154)              
Pd—C (4, 5), (II) 2.083 2.092 0.040 2.052 2.106 11  
Re—C (6), (I) 2.311 2.335 0.065 2.243 2.356 4  
Os—C see BUYNEO (2.221), CINKAL (2.215), EYPCOS (2.185)              
Ir—C see CAYGAK (2.420)              
Pt—C (4, 5), (II) 2.113 2.120 0.036 2.082 2.141 9 41
Au—C see BAJZAN (2.146), CEPYIF (2.175)             57
Hg—C see BAVMUG (2.122), TPHGDI10 (2.292)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.13.6.1 Tertiary alkyls (terminal CR3, R = any C)  
C—C   1.501 1.502 0.045 1.468 1.534 84 109
Fe—C (5, 6), (II) 2.127 2.128 0.027 2.098 2.153 6  
Co—C see COJBOS (2.154)              
Zn—C see COPLEY (2.050)              
Mo—C see CYPRMO (2.414)              
Pd—C (4), (II) 2.147 2.150 0.040 2.140 2.174 8  
Pt—C (4), (II) 2.148 2.139 0.028 2.133 2.162 9 41
Au—C see BENNOX (2.213), BUJXAF (2.197)             57

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.13.7.1 Trifluoromethyl (terminal CF3)  
C—F   1.347 1.343 0.030 1.329 1.355 22  
Pt—C (4, 5), (II) 2.098 2.087 0.057 2.056 2.146 5  

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.14.1 η2-Ethene (C2H4)  
C=C   1.392 1.390 0.044 1.363 1.415 43  
Co—C (5), (I) 2.035 2.033 0.012 2.025 2.048 4  
Ni—C (3, 4), (0) 1.985 1.978 0.025 1.970 1.989 18  
Cu—C (3, 4), (I) 2.010 2.011 0.011 2.001 2.019 6 12
Nb—C see CPETNB (2.278, 2.320)             54
Ru—C (6), (II) 2.198 2.204 0.022 2.174 2.215 4  
Rh—C (4, 5), (I) 2.129 2.135 0.033 2.091 2.160 12  
Ta—C see NPNTAB (2.228, 2.285)             54
W—C (5, 6), (-) 2.205 2.185 0.043 2.176 2.246 8  
Ir—C see CETPIR (2.124, 2.111)              
Pt—C (3, 4, ), (0, II) 2.172 2.176 0.042 2.143 2.193 28 41, 58

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.14.2 η2-Alkenes (CH2CHR, R = any C) 59
C=C   1.383 1.383 0.033 1.361 1.404 44  
Fe—C (5), (0) 2.090 2.088 0.012 2.079 2.102 4 58, 60
Co—C (5), (I) 2.084 2.085 0.034 2.052 2.115 4  
Ni—C (4, 5), (II) 2.035 2.039 0.053 1.984 2.082 4 9, 58, 61
Cu—C (3, ), (I) 2.060 2.061 0.025 2.046 2.080 6 12
Mo—C (6), (0, II) 2.282 2.271 0.027 2.265 2.310 4  
Ru—C (5, 6), (-) 2.198 2.190 0.034 2.171 2.232 4  
Rh—C (4, 6), (I, -) 2.172 2.164 0.058 2.118 2.216 10  
  (4), (I) 2.150 2.141 0.040 2.117 2.194 8  
Pd—C (4, 5), (II) 2.189 2.179 0.040 2.151 2.233 12  
Ag—C (3–5), (I) 2.535 2.542 0.050 2.486 2.582 6  
W—C (6), (0): all 2.386 2.410 0.080 2.302 2.454 10 30
  : short < 2.35 (trans to C=C) 2.299 2.298 0.010 2.290 2.308 4  
  : long > 2.40 (trans to CO) 2.443 2.434 0.036 2.412 2.484 6  
Ir—C see COPNIR (2.179, 2.162)              
Pt—C (4), (II) 2.179 2.173 0.051 2.139 2.205 22 41

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.14.3 η-Alkenes (CH2CR2, R = any C)  
C=C   1.387 1.396 0.029 1.354 1.413 8  
Fe—C (5), (0) 2.124 2.119 0.065 2.072 2.188 6 60
Ru—C see BOVLUT (2.168, 2.203)              
Pd—C see CARJOU (2.187, 2.107)              
Ag—C all CIXYAJ 2.421 2.419 0.081 2.345 2.499 4  

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.14.4 η2-Alkenes (CHRCHR, R = any C) 62
C=C   1.391 1.389 0.032 1.372 1.407 280  
V—C see EFMCPV (2.213, 2.186)              
Cr—C see MOBOCO10 (2.248, 2.300)              
Mn—C see CPTOMN (2.193, 2.203)              
Fe—C (5, 6), (0, II): all 2.134 2.143 0.063 2.079 2.183 22  
  : R electron withdrawing 2.067 2.072 0.022 2.041 2.087 8  
  : R = alkyl 2.172 2.169 0.041 2.144 2.195 14  
Co—C all NBPCCO 2.138 2.137 0.005 2.134 2.144 4  
Ni—C (3–5), (0, II): all 2.057 2.054 0.050 2.000 2.095 17 9, 58, 61
  : R electron withdrawing 1.991 1.997 0.015 1.979 2.000 5  
  :1,5-cod 2.084 2.089 0.028 2.052 2.107 12  
Cu—C (3, 4, ), (I): all 2.079 2.079 0.033 2.063 2.089 20 12
Mo—C (6), (0, II) : all 2.369 2.347 0.083 2.298 2.446 28  
  : trans to CO 2.468 2.463 0.039 2.428 2.499 10  
  : not trans to CO 2.314 2.310 0.034 2.284 2.346 18  
Ru—C : all 2.223 2.196 0.076 2.172 2.251 64 63
  : nbd, 1,5-cod only 2.191 2.187 0.036 2.167 2.206 49  
Rh—C (4–6, ), (I–III): all 2.157 2.143 0.049 2.123 2.188 206  
  : nbd, 1,5-cod only 2.156 2.143 0.047 2.122 2.189 184  
Pd—C (4), (II) 2.214 2.208 0.037 2.194 2.221 30  
Ag—C see BUZMUE (2.705, 2.611)              
W—C (6), (-) 2.430 2.430 0.033 2.400 2.457 6  
Re—C see BAXLER (2.275)              
Os—C : all R electron withdrawing 2.167 2.176 0.033 2.133 2.193 4  
Ir—C (4–6, ), (I, III): all 2.170 2.160 0.061 2.124 2.200 94  
  : 1,5-cod only 2.163 2.160 0.051 2.124 2.186 76  
Pt—C (4, 5, ), (0, II): all 2.209 2.223 0.056 2.173 2.252 52 41, 58
  : 1,5-cod only 2.230 2.236 0.039 2.193 2.254 40  

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.14.5 η2-Alkenes (CHRCR2, R = any C)  
C=C   1.411 1.403 0.025 1.392 1.427 12  
Mo—C see OCTCMO10 (2.211, 2.227)              
Ru—C see CXFMPR (2.171, 2.184)              
Rh—C (4, 5), (I) 2.130 2.121 0.023 2.111 2.155 14  
Ir—C all COTFEW 2.148 2.150 0.020 2.130 2.165 4  
Pt—C see COTFPT (2.059, 2.072)             41, 58

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.14.6 η2-Alkenes (CR2CR2, R = any C)  
C=C   1.436 1.438 0.044 1.415 1.454 15  
Fe—C : all 2.144 2.085 0.127 2.048 2.269 8  
  : excluding trans to CO 2.079 2.058 0.045 2.045 2.121 6  
Co—C see EXPHCO (2.084, 2.134)              
Mo—C see CPOMOA (2.231, 2.234)              
Rh—C (4, 5), (I) 2.175 2.173 0.025 2.153 2.199 4  
Pd—C (4), (II) 2.248 2.258 0.055 2.191 2.296 4  
Ag—C see BUGGAL (2.472, 2.632)              
Ir—C see IRCNIR (2.098, 2.130)              
Pt—C   2.130 2.128 0.026 2.106 2.156 4 41, 58
Hg—C see BODYEY (2.556, 2.577)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.14.7.1 η2-Allenes (R2CCCR2)§  
Cα=Cβ (coordinated) 1.403 1.403 0.028 1.375 1.431 5  
Cβ=Cγ (free) 1.319 1.321 0.010 1.311 1.327 5  
Fe—Cα see FPCYTP10 (1.982)              
—Cβ see FPCYTP10 (1.897)              
Rh—Cα see MARHAA10 (2.177, 2.178)              
—Cβ see MARHAA10 (2.032, 2.027)              
Pd—Cα see ALETPD (2.118)              
—Cβ see ALETPD (2.068)              
Pt—Cα see MALLPT (2.107)             41
—Cβ see MALLPT (2.049)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.15.1.1 Alkynes (η2-C2R2, R = any C) 64
C[triple bond]C all 1.285 1.287 0.030 1.269 1.299 73  
  2e donor 1.269 1.271 0.034 1.242 1.284 23  
  3e donor 1.285 1.292 0.024 1.268 1.299 15  
  4e donor 1.304 1.309 0.027 1.280 1.321 15  
V—C see CPFVLV (2.076)              
Cr—C all PHACCS 1.960 1.960 0.009 1.952 1.969 6  
Mn—C see HDYCMN (1.239)              
Co—C see ACNCOB20 (1.977, 1.981), BETCUY10 (1.847, 1.856)              
Cu—C (3), (1): R = SiMe3, H 2.019 2.020 0.029 1.994 2.043 5 12
Nb—C (6, 8), (III): R = Ph 2.082 2.054 0.061 2.041 2.148 8 54
Mo—C varying electron donation (2–4e): all 2.078 2.072 0.050 2.043 2.143 40 65
  2e donor 2.129 2.131 0.031 2.099 2.148 12  
  3e donor 2.071 2.066 0.033 2.053 2.082 12  
  4e donor 2.027 2.035 0.028 1.997 2.049 12  
Rh—C : R = Ph, CF3 2.041 2.045 0.015 2.030 2.051 6  
Pd—C see FMEACA10 (2.040, 2.053)              
Ta—C   2.059 2.064 0.024 2.032 2.079 6 54
W—C varying electron donation (2–4e): all 2.060 2.059 0.036 2.034 2.083 36 65
  2e donor 2.080 2.076 0.041 2.059 2.104 14  
  3e donor 2.066 2.066 0.016 2.053 2.078 12  
  4e donor 2.025 2.022 0.014 2.013 2.036 10  
Re—C   2.043 2.042 0.022 2.029 2.063 6  
Ir—C   2.083 2.083 0.041 2.044 2.122 4  
Pt—C   2.025 2.029 0.016 2.020 2.037 18 41

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.15.1.2 Alkynes (μ22, η2′-C2R2)§ 64
C[triple bond]C   1.353 1.355 0.031 1.337 1.365 29  
Co—C   1.954 1.940 0.033 1.930 1.966 47  
Ni—C all FLCPNI 1.910 1.909 0.011 1.901 1.921 4 61
Mo—C   2.171 2.178 0.050 2.137 2.199 32  
Rh—C all CFBYRH 2.054 2.056 0.029 2.026 2.081 4  
Ta—C see ACTHTA (2.217, 2.418)              
W—C all: (show twisting from C2vC2) 2.122 2.099 0.102 2.050 2.214 12  
  excluding CAMLAD 2.117 2.099 0.059 2.086 2.158 8  

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.15.1.3 Alkynes (μ21, η1′-C2R2)§ 64
C[triple bond]C   1.315 1.316 0.024 1.301 1.340 14  
Co—C see CAHHAU (2.066)              
Ru—C   2.084 2.091 0.016 2.068 2.094 4  
Rh—C   2.021 2.001 0.041 1.992 2.064 6  
Ir—C   2.112 2.109 0.041 2.082 2.156 8  
Pt—C   2.059 2.056 0.009 2.051 2.068 5 41

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.16.1 η3-Allyls (R2C.CR.CR2)§  
C1—C2   1.404 1.404 0.035 1.388 1.421 375  
V—C1 all ALCPPV 2.349 2.352 0.013 2.342 2.357 6  
—C2 (2.222, 2.228, 2.245)              
Cr—C1 see CAMWOC (2.171, 2.247)              
—C2 (2.193)              
Mn—C1 (6), (I) 2.223 2.227 0.018 2.205 2.233 8  
—C2   2.120 2.120 0.004 2.116 2.124 4  
Fe—C1 (5, 6), (0–II) 2.155 2.155 0.044 2.135 2.181 70 60
—C2   2.068 2.070 0.033 2.048 2.092 36  
Co—C1   2.082 2.083 0.029 2.054 2.112 17  
—C2   2.000 2.007 0.021 1.985 2.015 9  
Ni—C1 (4, 5), (-) 2.044 2.031 0.057 2.005 2.075 34 66
—C2   1.962 1.967 0.040 1.937 1.995 17  
Zr—C1 (7), (II) 2.472 2.469 0.028 2.444 2.498 8  
—C2   2.470 2.476 0.019 2.450 2.485 4  
Mo—C1 (6, 7), (-): most (7), (II) 2.353 2.352 0.057 2.321 2.375 73  
—C2   2.244 2.234 0.048 2.214 2.274 37  
Ru—C1 (5, 6), (-): most (6), (II) 2.254 2.247 0.058 2.209 2.293 27  
—C2   2.168 2.174 0.041 2.130 2.197 14  
Rh—C1 (4–6), (I, III) 2.191 2.193 0.048 2.151 2.233 24  
—C2   2.148 2.138 0.041 2.122 2.159 12  
Pd—C1 : most (4), (II) 2.142 2.133 0.041 2.115 2.172 62  
—C2   2.118 2.116 0.034 2.100 2.143 31  
W—C1 (7), (II) 2.303 2.303 0.053 2.256 2.339 16  
—C2   2.240 2.229 0.061 2.182 2.293 8  
Ir—C1 (5, 6), (I, III): all 2.212 2.188 0.048 2.175 2.268 8  
—C2   2.168 2.165 0.059 2.113 2.225 4  
—C1 (5), (I) 2.174 2.176 0.006 2.167 2.179 4  
—C2 (2.100, 2.152)              
—C1 (6), (III) 2.249 2.260 0.039 2.208 2.279 4  
—C2 (2.241, 2.178)              
Pt—C1 (4), (II) 2.194 2.191 0.044 2.159 2.242 10 41
—C2   2.170 2.184 0.034 2.138 2.194 5  
U—C1 (7, 9), (IV) 2.670 2.663 0.038 2.640 2.701 10  
—C2   2.748 2.781 0.070 2.674 2.806 5  

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.17.1 η4-Cyclobutadiene (C4H4)  
C—C   1.423 1.434 0.035 1.409 1.441 16  
Fe—C   2.027 2.031 0.026 2.020 2.039 12  
—centroid (1.759, 1.757, 1.763)              
Co—C   1.990 1.974 0.034 1.965 2.024 6  
—centroid (1.682, 1.748)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.17.2 η4-Cyclobutadienes (C4R4, R4 ≠ H4)  
C—C   1.462 1.464 0.019 1.455 1.472 136  
Mn—C all BUKGET 2.107 2.109 0.019 2.088 2.124 4  
—centroid (1.837)              
Fe—C (5), (0) 2.044 2.039 0.025 2.024 2.066 12 50
—centroid (1.760, 1.766, 1.779)              
Co—C (5), (I) 1.989 1.987 0.026 1.975 2.003 51  
—centroid   1.704 1.694 0.037 1.689 1.706 13  
Ni—C (4, 5), most (II) 2.027 2.025 0.036 2.001 2.060 16 67
—centroid   1.742 1.740 0.018 1.727 1.761 4  
Mo—C (6), (0, I) 2.280 2.270 0.041 2.249 2.299 16  
—centroid   2.032 2.033 0.036 1.998 2.065 4  
—C (6), (0) 2.308 2.298 0.040 2.276 2.338 8  
—centroid (2.060, 2.066)              
—C (6), (I) 2.253 2.252 0.018 2.240 2.269 8  
—centroid (1.995, 2.006)              
Ru—C (5, 6), (0, II) 2.224 2.184 0.086 2.168 2.312 8  
—centroid (2.006, 1.926)              
—C (5), (0): all COCLEL 2.261 2.256 0.116 2.159 2.368 4  
—C (6), (II): all CIMVID 2.188 2.184 0.015 2.176 2.204 4  
Rh—C (5), (I) 2.114 2.105 0.025 2.102 2.120 8  
—centroid (1.850, 1.829)              
Pd—C (4, 5), (II) 2.148 2.135 0.065 2.106 2.160 16  
—centroid   1.887 1.873 0.042 1.857 1.932 4  
—C (5), (II) 2.130 2.135 0.027 2.106 2.145 12  
Pt—C all CBFPPT10 2.219 2.214 0.096 2.129 2.314 4  
—centroid (1.963)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.17.3 η4-1,3-Butadienes (R2C.CR.CR.CR2)§ 68
C1—C2   1.420 1.420 0.021 1.409 1.433 213  
C2—C2   1.405 1.404 0.023 1.392 1.416 108  
Cr—C1   2.332 2.349 0.046 2.277 2.370 6  
—C2   2.147 2.134 0.043 2.110 2.200 6  
Mn—C1 (5), (0) 2.134 2.135 0.007 2.128 2.141 8  
—C2   2.080 2.071 0.025 2.066 2.106 8  
Fe—C1   2.130 2.128 0.029 2.111 2.148 113 60
—C2   2.059 2.058 0.018 2.050 2.068 113  
Co—C1 (5, 6), (0, I) 2.089 2.102 0.045 2.061 2.125 12  
—C2   2.015 2.003 0.033 1.994 2.018 12  
—C1 excluding 2 < 2.015 2.105 2.106 0.025 2.095 2.132 10  
—C2 excluding 2 > 2.075 2.001 1.998 0.012 1.993 2.013 10  
Ni—C1 see BUJFUH (2.360, 2.106)              
—C2 see BUJFUH (2.074, 2.018)              
Zr—C1 (7, 8), (-): all 2.402 2.323 0.162 2.305 2.526 14 69
—C2   2.522 2.549 0.120 2.397 2.582 14  
—C1 structures with Zr—C1 < Zr—C2 2.314 2.311 0.021 2.298 2.326 10  
—C2   2.582 2.563 0.078 2.542 2.624 10  
Mo—C1 (5–7), (-) 2.356 2.364 0.052 2.331 2.378 20  
—C2   2.280 2.280 0.038 2.251 2.309 20  
Ru—C1 (5, 6), (0, II) 2.254 2.246 0.060 2.223 2.267 17  
—C2   2.181 2.173 0.050 2.155 2.194 17  
—C1 excluding 2 > 2.385 2.236 2.233 0.033 2.218 2.265 15  
—C2 excluding 2 > 2.29 2.165 2.169 0.025 2.155 2.180 15  
Rh—C1   2.214 2.224 0.047 2.165 2.252 4  
—C2   2.177 2.198 0.043 2.134 2.199 4  
Hf—C1 (6), (0): all 2.369 2.368 0.019 2.350 2.387 8 69
—C2   2.400 2.400 0.006 2.395 2.407 8  
W—C1 see HPMXCW10 (2.453, 2.460)              
—C2 see HPMXCW10 (2.335, 2.263)              
Re—C1 see BIBJEB (2.310, 2.277)              
—C2 see BIBJEB (2.276, 2.258)              
Os—C1 see OXBUDC10 (2.243, 2.300)              
—C2 see OXBUDC10 (2.198, 2.240)              
Ir—C1 see BUHIPI (2.277, 2.162); CBUTIR (2.186)              
—C2 see BUHIPI (2.141, 2.202); CBUTIR (2.153)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.17.4 η4-1,5-Cyclooctadiene (1,5-cod) 62
  (see 3.14.4)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.17.5 η4-Norbornadiene (nbd) 62
  (see 3.14.4)              

BondSubstructure (coordination number, oxidation state, comment)dmσqlqunNote
3.18.1 η5-Cyclopentadienyl (C5H5)  
C—C   1.397 1.398 0.028 1.380 1.415 6804  
Sc—C all TCYPSC10 2.494 2.499 0.023 2.473 2.513 10  
—centroid (2.189, 2.194)              
Ti—C   2.374 2.375 0.031 2.354 2.396 832  
—centroid   2.062 2.061 0.026 2.044 2.082 170  
V—C   2.281 2.281 0.026 2.260 2.301 226  
—centroid   1.952 1.950 0.020 1.938 1.970 46  
Cr—C   2.225 2.226 0.033 2.197 2.250 295  
—centroid   1.876 1.882 0.029 1.847 1.898 61  
Mn—C : all 2.166 2.149 0.094 2.127 2.164 321 30
—centroid : all 1.824 1.786 0.132 1.775 1.798 67 30
—C (-), (-): low spin 2.143 2.146 0.026 2.125 2.161 300  
—centroid : low spin 1.783 1.784 0.018 1.774 1.794 61  
—C : MnII, high spin 2.511 2.499 0.052 2.479 2.541 20  
—centroid   2.237 2.229 0.051 2.196 2.262 6  
Fe—C   2.080 2.088 0.035 2.052 2.106 1309 60
—centroid   1.706 1.721 0.039 1.662 1.735 265  
Co—C   2.068 2.066 0.031 2.045 2.089 740  
—centroid   1.696 1.692 0.029 1.676 1.716 152  
Ni—C   2.116 2.113 0.033 2.093 2.138 315 70
—centroid   1.748 1.750 0.025 1.734 1.762 65  
Cu—C all TPCYCU 2.211 2.205 0.018 2.195 2.231 5  
—centroid (1.864)              
Zn—C   2.348 2.332 0.080 2.299 2.440 15  
—centroid   2.044 2.038 0.027 2.021 2.072 4  
Y—C   2.649 2.646 0.040 2.626 2.668 75  
—centroid   2.382 2.379 0.041 2.356 2.386 15  
Zr—C   2.529 2.529 0.031 2.510 2.546 649 71
—centroid   2.236 2.233 0.023 2.220 2.251 132  
—C excluding BOYLUW 2.528 2.528 0.026 2.510 2.545 638  
—centroid excluding BOYLUW 2.235 2.232 0.022 2.220 2.250 131  
Nb—C   2.408 2.406 0.037 2.385 2.435 353 54
—centroid   2.093 2.093 0.029 2.075 2.110 71  
Mo—C   2.336 2.338 0.042 2.304 2.368 1363  
—centroid   2.011 2.010 0.033 1.992 2.026 278  
Ru—C   2.236 2.240 0.041 2.204 2.267 284  
—centroid   1.892 1.898 0.042 1.857 1.929 58  
Rh—C   2.239 2.236 0.037 2.218 2.264 256  
—centroid   1.895 1.898 0.032 1.879 1.914 53  
Pd—C all BUPTEL 2.344 2.350 0.050 2.303 2.381 5  
—centroid (2.015)              
Pr—C all CXINPR10 2.778 2.765 0.026 2.760 2.801 15 1, 21
—centroid (2.526, 2.527, 2.526)              
Gd—C all CPTHGD10 2.738 2.744 0.025 2.722 2.747 15 1, 21
—centroid (2.472, 2.490, 2.494)              
Er—C all BOBWAQ 2.667 2.665 0.005 2.663 2.671 5 1, 21
—centroid (2.391)              
Yb—C (8, 10), (-) 2.657 2.642 0.047 2.621 2.693 25 1, 21
—centroid   2.383 2.383 0.043 2.340 2.426 5  
Lu—C all OHCPLU 2.600 2.599 0.018 2.584 2.615 10 1, 21
—centroid