Structure of 2-methyl-3-phenyl-3-[(tri-p-tolyl)germyl] propanoic acid, (p-CH₃C₆H₄)₃GeCH(Ph)CH(Me)CO ₂H. CHCl₃

In the title compound, one molecule of CHCl₃, is also present in each asymmetric unit. The germanium adopts a distorted tetrahedral coordination geometry [C-Ge-C: 106.5(1) - 111.7(1)^o]. Ge-C bond lengths between the germanium and the three p-tolyl groups are identical within experimental error [1.951 (3) - 1.955(3) Å], however Ge-C(22) of the substituted propanoic acid is significantly longer [1.997(3) Å]. The molecule dimerises through hydrogen bonds between carboxylic acid groups, in a conventional manner. The hydrogen bond is relatively strong [O(1)...O(2′): 2.661(2); H(2A)-O(1′): 1.81(4) Å; <O(2)-H(2A)-O(1): 161(4)^o] and delocalisation of the double-bond character renders the two C-O bond lengths indistinguishable [C(31)-O(1): 1.255(4); C(31)-O(2): 1.260(4)Å]. The mode of dimerisation thus contrasts with the situation in the related species Cl₃GeCH(Ph)CH₂CO₂H where chlorine atoms act as the hydrogen bond acceptors. The solvent³(CHCl₃) is loosely associated with the carboxylic acid group [H(32)...O(2): 2.53 Å] though this length, along with <C(32)-H(32)...O(2) (129.5^o), rules out any meaningful hydrogen bond.