Structural analysis of bisphenol-A and its methylene, sulfur, and oxygen bridged bisphenol analogs

The molecular structures of bisphenol-A, C(CH3)(2)(P-C6H4OH)(2) (monoclinic, P2(1) /n, a = 11.1940(6) angstrom, b = 18.738(1) angstrom, c = 17.8623(9) angstrom, beta = 100.571 (1)degrees), its methylene (CH2) and heteroatom (S, O) bridged analogs, CH2(p-C6H4OH)(2) (monoclinic, P2(1)/n, a = 5.4351(1) angstrom, b = 20.7895(3) angstrom, c = 8.8432(1) angstrom, beta = 93.419(1)degrees), S(p-C6H4OH)(2) (monoclinic, P2(1)/n, a = 5.5115(1) angstrom, b = 21.0666(2) angstrom, c = 8.6917(1) angstrom, beta = 92.962(1)degrees) and O(P-C6H4OH)(2) (orthorhombic, Pbcn, a = 5.2745(5) angstrom, b = 8.2724(8) angstrom, c = 22.085(2) angstrom), have been determined by X-ray diffraction at 115 K, revealing structural differences in the series of compounds. The results show that the C-ary1-X(bridge)7C(ary1) angles (X-bridge = C(CH3)(2), CH2, S, O) span a range greater than 14 degrees. The dihedral angle between the planes of the hydroxyphenyl groups also varies according to the identity of the bridging group, varying from 67.24(2)degrees in S(p-C6H4OH)(2) to 85.82(4)degrees in C(CH3)(2)(p-C6H4OH)(2). In addition, the pitch angle, which more accurately describes the propeller-like nature of these bisphenolic compounds, varies from 39.88(3)degrees in S(p-C6H4OH)(2) to 59.62(7)degrees in C(CH3)(2)(p-C6H4OH)(2). Ab initio electronic structure calculations predict very similar bond lengths and angles to those observed crystallographically; however, the predicted dihedral angles and pitch angles are quite different, suggesting that these features are greatly influenced by crystal packing.