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, p. 812

Section 9.6.1. Introduction

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

9.6.1. Introduction

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The determination of molecular geometry is of vital importance to our understanding of chemical structure and bonding. The majority of experimental data have come from X-ray and neutron diffraction, microwave spectroscopy, and electron diffraction. Over the years, compilations of results from these techniques have appeared sporadically. The first major compilation was Chemical Society Special Publication No. 11: Tables of Interatomic Distances and Configuration in Molecules and Ions (Sutton, 1958[link]). This volume summarized results obtained by diffraction and spectroscopic methods prior to 1956; a supplementary volume (Sutton, 1965[link]) extended this coverage to 1959. Summary tables of bond lengths between carbon and other elements were also published in Volume III of International Tables for X-ray Crystallography (Kennard, 1962[link]). Some years later, the Cambridge Crystallographic Data Centre (Allen, Bellard, Brice, Cartwright, Doubleday, Higgs, Hummelink, Hummelink-Peters, Kennard, Motherwell, Rodgers & Watson, 1979[link]) produced an atlas-style compendium of all organic, organometallic and metal-complex crystal structures published in the period 1960–1965 (Kennard, Watson, Allen, Isaacs, Motherwell, Pettersen & Town, 1972[link]). More recently, a survey of geometries determined by spectroscopic methods (Harmony, Laurie, Kuczkowski, Schwendemann, Ramsay, Lovas, Lafferty & Maki, 1979[link]) has extended coverage in this area to mid-1977. A notable compendium of structural data, without geometric information, was given in Comprehensive Organometallic Chemistry (Bruce, 1981[link]), covering all complexes with metal–carbon bonds. The BIDICS (Brown, Brown & Hawthorne, 1982[link]) series, which finished in 1981, provided for some years a full coverage of metal complexes giving both bibliographic and geometric information. There have also been valuable annual summaries, without geometric information, on the structures of organometallic compounds determined by diffraction methods (Russell, 1988[link]).

The production of further comprehensive compendia of X-ray and neutron diffraction results has been precluded by the steep rise in the number of published crystal structures, as illustrated by Fig. 9.6.1.1[link]. Print compilations have been effectively superseded by computerized databases. In particular, the Cambridge Structural Database now contains bibliographic, chemical, and numerical results for some 86 000 organo-carbon crystal structures. This machine-readable file fulfils the function of a comprehensive structure-by-structure compendium of molecular geometries. However, the amount of data now held in the CSD is so large that there is also a need for concise, printed tabulations of average molecular dimensions.

[Figure 9.6.1.1]

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Growth of the Cambridge Structural Database as number of entries (Nent) added annually. The structures containing d- or f-block metals are indicated by shading.

The only tables of average geometry in general use are those contained in the Chemical Society Special Publications of 1958 and 1965 (Sutton, 1958[link], 1965[link]), which list mean bond lengths for a variety of atom pairs and functional groups. Since these early tables were based on data obtained before 1960, we have used the CSD to prepare a new table of average bond lengths in organic compounds (see Chapter 9.5[link] ) and in metal complexes. The table given here (Table 9.6.3.3[link]) specifically lists average lengths for metal–ligand distances, together with intra-ligand distances, involving bonds between the d- and f-block metals (Sc–Zn, Y–Cd, La–Hg, Ce–Lu, Th–U) and atoms H, B, C, N, O, F, Si, P, S, Cl, As, Se, Br, Te, and I of ligands. Mean values are presented for 324 different bond types involving such metal–ligand bonds.

References

Allen, F. H., Bellard, S., Brice, M. D., Cartwright, B. A., Doubleday, A., Higgs, H., Hummelink, T., Hummelink-Peters, B. G., Kennard, O., Motherwell, W. D. S., Rodgers, J. R. & Watson, D. G. (1979). The Cambridge Crystallographic Data Centre: computer-based search, retrieval, analysis and display of information. Acta Cryst. B35, 2331–2339.
Brown, I. D., Brown, M. C. & Hawthorne, F. C. (1982). BIDICS-1981, Bond index to the determinations of inorganic crystal structures. Institute for Materials Research, Hamilton, Ontario, Canada.
Bruce, M. I. (1981). Comprehensive organometallic chemistry, Vol. 9, pp. 1209–1520. London: Pergamon Press.
Harmony, M. D., Laurie, R. W., Kuczkowski, R. L., Schwendemann, R. H., Ramsay, D. A., Lovas, F. J., Lafferty, W. J. & Maki, A. G. (1979). Molecular structures of gas-phase polyatomic molecules determined by spectroscopic methods. J. Phys. Chem. Ref. Data, 8, 619–721.
Kennard, O. (1962). Tables of bond lengths between carbon and other elements. International tables for X-ray crystallography, Vol. III, pp. 275–276. Birmingham: Kynoch Press.
Kennard, O., Watson, D. G., Allen, F. H., Isaacs, N. W., Motherwell, W. D. S., Pettersen, R. C. & Town, W. G. (1972). Molecular structures and dimensions, Vol. A1. Interatomic distances, 1960–65. Utrecht: Oosthoek.
Russell, D. R. (1988). Specialist periodical reports, organometallic chemistry, pp. 427–525. London: Royal Society of Chemistry.
Sutton, L. E. (1958). Tables of interatomic distances and configuration in molecules and ions. Spec. Publ. No. 11. London: Chemical Society.
Sutton, L. E. (1965). Tables of interatomic distances and configuration in molecules and ions. Spec. Publ. No. 18. London: Chemical Society.








































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