Assessment of the metal atom coordination sphere occupation degree in triarylantimony dicarboxylates and 2-oxo-bis[(carboxylato)triarylantimony]

On the basis of the X-ray diffraction analysis data for forty triarylantimony dicarboxylates and seven μ2-oxo-bis[(carboxylato)triarylantimony], a quantitative assessment of the metal atom coordination sphere occupation degree in the model of ligand solid angles was carried out for the first time to identify the relationship between the coordination space (G-factor) occupation degree and the presence of intramolecular interactions leading to distortion of molecular geometric characteristics. The G-factor (%) for triarylantimony dicarboxylate molecules varied within the range of 80.19-94.90%. The most typical values of the G-factor are from 86 to 88.5%. The most saturated coordination spheres of a central atom (more than 90%) were found for the compounds containing methoxy groups in aryl ligands, which coordinate oxygen atoms to the antimony atom. High values of the G-factor (89.41-91.34%) have been found in structures in which the coordination sphere saturation is due to the Sb⋅⋅⋅O(=С) strong non-valent interactions (2.543(1)-2.856(6) Å). Steric congestion leads to distortion of the molecular geometric characteristics, in particular to an increase in one of the CSbC equatorial angles up to 159.3(1)º. In compounds of the general formula [Ar3SbOC(O)R]2O, the G-factor varies within the range from 86.95 to 91.05%, which is 2-4% higher than in triarylantimony dicarboxylates with similar carboxylate ligands. The G-factor of molecules with a linear structure of the Sb-O-Sb central fragment is smaller on average than with an angular one. Complete tables of atomic coordinates, bond lengths and bond angles are deposited in the Cambridge Crystallographic Data Centre (№ 1821409 (1), 1979844 (2), 1980334 (3), 2121388 (4), 850119 (5), 2089436 (6), 2127828 (7), 1573780 (8), 1573014 (9), 1573486 (10),1883064 (11),1883072 (12), 2055551 (13), 1883065 (14), 1883074 (15), 1573983 (16), 1031560 (17), 2055594 (18), 1015668 (19), 1010868 (20), 1919919 (21), 1880056 (22), 1884115 (23), 1462857 (24), 1576023 (25), 1478437 (26), 1576022 (27), 1457885 (28), 1457894 (29), 1576967 (30), 2178731 (31), 1462849 (32), 2045964 (33), 2060290 (34), 2074511 (35), 2048157 (36), 2041587 (37), 2055804 (38), 2051941 (39), 2077192 (40), 1840588 (41), 2217059 (42), 2225642 (43), 2233180 (44), 2233088 (45), 1841803 (46), 1840585 (47); deposit@ccdc.cam.ac.uk; http://www.ccdc.cam.ac.uk).