Study of charges on heteroatoms in organic compounds of the second-row elements by X-ray fluorescence spectroscopy 12. Complexes of antimony pentachloride

The characteristic features of the electronic structure of SbCl₅L complexes has been studied in comparison with those of the SnCl₄L₂ and TiCl₄L₂ complexes. The results of X-ray structural analysis were correlated with the heats of complexation, the data of Mössbauer spectroscopy, derivatography, quantum-chemical PM3 calculations, and stretching frequencies of the donor-acceptor bonds. Based on these data, the contributions of different effects to the stabilities of complexes were determined, complexation enthalpies previously unknown were calculated, and a conclusion was drawn that the electron density transfer from the donor to the acceptor is small. The charge effect of the donor consists primarily in polarization of the acceptor bonds, this polarization decreases as a result of the change in the geometry of the acceptor upon complexation. The relative stabilities of the complexes with dimethyl sulfide were determined using a unique internal standard technique.