Artificial manipulation of apparent bond lengths as determined by single-crystal x-ray diffraction

Single crystals composed of solid solutions of pairs of the complexes {eta-3-HB(3-Bu(t)pz)3}ZnCl, {eta-3-HB(3-Bu(t)pz)3}ZnI, and {eta-3-HB(3-Bu(t)pz)3}ZnCH3 [3-Bu(t)pz = 3-C3N2H2Bu(t)], over a range of compositions, have been examined by X-ray diffraction. In each case the presence of the impurity is manifested by the observation of an apparent Zn-X bond length that is intermediate between the two possible extremes for the pair of complexes involved. As expected the relationship between the apparent bond length and composition is not linear but is weighted by the relative scattering powers of the disordered groups.