. Assessment of the metal atom coordination sphere occupation degree in the molecules of triarylantimony diaroxydes and μ2-oxo-bis[(aroxo)triarylantimony]

Abstract

Based on the X-ray diffraction analysis data of single crystalstwenty-one triarylantimony diaroxides and eleven μ2-oxo-bis[(aroxo)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 intramolecular interactions presence leading to distortion of the molecular geometric characteristics. The G-factor (%) for triarylantimony diaroxide molecules varies within 83.96–89.97 %, which indicates that the coordination sphere of the central atom is sterically saturated. The maximum values of the G-factor (88 and 90 %) are observed in molecules in which intramolecular π···π-interactions of the aromatic rings of the aryl and aroxide ligands take place. The large value of the G-factor (89.54 %) in the structure of tris(para-tolyl)antimony bis(2,4,6-tribromophenoxide) is obviously due to the large steric volume of the aroxide ligands. In compounds of the general formula (Ar3SbOAr)2O, the G-factor varies within 87.93–96.14 %, which is 2–4 % greater than in triarylantimony diaroxides. The highest values of the G-factor correspond to compounds in which intramolecular contacts Sb···OMe are observed (94.03–96.14 %) or bulky aroxide ligands are present (90.68–92.09 %). Complete tables of atomic coordinates, bond lengths and bond angles are deposited in the Cambridge Crystallographic Data Centre (№2179019 (1), 1476218 (2), 2217062 (3), 1474591 (4), 1483785 (5), 2082753 (6), 1982326 (7), 1470829 (8), 1060629 (9), 1060381 (10), 1474589 (11), 1470476 (12), 1472954 (13), 1971836 (14), 1047500 (15), 1048172 (16), 1048212 (17), 1062337 (18), 1473422 (19), 1473384 (20), 2205070 (21), 1890704 (22), 1976209 (23), 1465099 (24), 1890706 (25), 1060994 (26), 2178725 (27), 1465132 (28), 2064392 (29), 1986167 (30), 1471841 (31), 1064064 (32); deposit@ccdc.cam.ac.uk; http://www.ccdc.cam.ac.uk).