Crystal structures of the acid salts of some monobasic acids. Part XVI. Potassium hydrogen bis-m-chlorobenzoate

Abstract

The title compound crystallises in space group C2/c with Z= 4 in a cell of dimensions: a= 32·55, b= 3·83, c= 11·45 Å, β= 94·6°. It proves to be a Type A acid salt with a crystal structure surprisingly similar to that of potassium hydrogen di-p-chlorobenzoate. Structure analysis was based on 1283 non-zero X-ray reflexion intensities obtained by diffractometer measurements and R was 5·9%. There is a hydrogen bond across a centre of symmetry between equivalent chlorobenzoate residues, with O ⋯ H ⋯ O 2·437(6)Å. This may be another example of a genuinely symmetrical hydrogen bond.