Hydrogen bonding in diphenylmethanols, RCPh2OH: structures of monomeric (4-biphenyl)diphenylmethanol and diphenyl(2-pyridyl)methanol, dimeric 1,1,3-triphenylpropyn-1-ol, trimeric 2-methyl-1,1-diphenylpropan-1-ol, tetrameric diphenyl(2-thienyl)methanol, hexameric bis(pentafluorophenyl)methanol (at 293 and 173 K) and polymeric diphenylmethanol

Abstract

(4-Biphenyl)diphenylmethanol (1), C 25 H 20 O, orthorhombic, P2 1 2 1 2 1 , a = 8.3580 (11), b = 13.8976(17), c = 15.5915 (12) A, Z = 4, R = 0.032 for 1146 observations [I > 3σ(I)] : the structure contains isolated monomers with no hydrogen bonding. Diphenyl(2-pyridyl)methanol (2), C 18 H 15 NO, monoclinic, P2 1 /c, a = 8.1899 (8), b = 14.855 (2), c = 11.6069 (15) A, β = 96.344(8)°, Z = 4, R = 0.049 for 879 observations [I > 3σ(I)] : the structure consists of isolated monomers in which the intramolecular O-H...N hydrogen-bond motif has graph set S(5). 1,1,3-Triphenylpropyn-1-ol (3), C 21 H 16 O, monoclinic, P2 1 /c, a = 5.9794(12), b = 9.953 (3), c = 26.420 (3) A, β = 91.365 (12)°, Z = 4, R = 0.039 for 971 observations [I > 2σ(I)] : the structure contains centrosymmetric dimers held together by O-H...π(arene) hydrogen bonds involving one of the phenyl groups, rather than the propargyl group. 2-Methyl-1,1-diphenylpropan-1-ol (4), C 16 H 18 O, trigonal, P31c, a = 13.9232(17), c = 12.0200(19) A, Z = 6, R = 0.031 for 763 observations [I > 3σ(I)] : the structure consists of cyclic hydrogen-bonded trimers with crystallographic threefold symmetry and disordered hydroxyl H atoms in a motif with graph set R 3 3 (6) : the O...O distance in the trimers is 2.864 (7) A. Diphenyl(2-thienyl)methanol (5), C 17 H 14 OS, rhombohedral, R3, a = 19.20(1), c = 26.48(1)A, Z = 24 : this compound is isomorphous and isostructural with triphenylmethanol, Ph 3 COH, and forms hydrogen-bonded tetrahedral tetramers. Bis(pentafluorophenyl)methanol (6), C 13 H 2 F 10 O, rhombohedral, R3, a = 26.113(3), c = 9.788 (3) A (at 293K), R = 0.068 for 1214 observations [I > 2σ(I)] ; a = 26.006 (4), c = 9.5941(11) A (at 173 K), R = 0.072 for 1889 observations [I > 2σ(I)], Z = 18 ; the structure consists of coaxial stacks of cyclic hydrogen-bonded hexamers, each of 3 symmetry, and with a hydrogen-bond motif of graph set R 6 6 (12). Within the hexamers, the molecules are disordered over two orientations in the ratio 0.779 (3) :0.221 (3) at 293 K and 0.776 (2) :0.224 (2) at 173 K : the O...O distance is 2.702 (4) A at 293 K and 2.683(4)A at 173K. Diphenylmethanol (7), C 13 H 12 O, orthorhombic, P22 1 2 1 , a = 5.1300(10), b = 18.650(5), c = 21.168 (6) A, Z = 8, R = 0.035 for 1487 observations [I >3σ(I)] : there are two molecules in the asymmetric unit and the molecules are linked by hydrogen bonds into spiral chains having graph set C(4) and lying parallel to the a-axis ; the O...O distances within the chains are 2.826(3) and 2.878 (3) A.