The crystal structure of orthoboric acid has been redetermined.The triclinic unit cell, containing four molecules B(OH)3, has dimensions a 1 = 7.039 A, a~----7.053A, a3= 6.578 A, al= 92"58 °, a2--101"17 °, ~a--119"83°-The 42 parameters in the structure were determined with the aid of precise intensity measurements made with a Geiger-counter spectrometer.The structure is built up of B(OH)3 molecules.These molecules are linked together by hydroxyl bonds, O-I-I-.. O, to form endless layers of nearly hexagonal symmetry.The structure can be regarded as a stack of such layers 3.181 A apart and held together by van tier Waals forces.The bond distances within a B(OH)3 molecule are B-O = 1.361A, O-H----0.88A, with a value of 114 ° for the oxygen bond angle.The O-H. • • O distance between molecules is 2.720 A.
No takes yet. Share an insight, caveat, or question.
W. H. Zachariasen (1954) studied this question.