Inorganic Coordination Polymers. XIII. Chromium(III) Halobis(phosphinates)

摘要

Mu-Halo-bis(me-phosphinato)-chromium(III) polymers, (CrX(OPRR'O)2)n (with R=R'C6H5, R=R'=C8H17, and R=CH3 and R'=C6H5; X=Cl, Br, and I), have been investigated. The chloro polymers were preapred by the reaction of anhydrous chromium(III) chloride with the appropriate phosphinic acid. The bromo and iodo polymers were prepared by oxidizing chromium(II) phosphinates with bromine and iodine, respectively. The chloro and bromo diphenylphosphinato polymers are soluble in common organic solvents and have molecular weights corresponding to degrees of polymerization of 10-12. They are hydrolytically unstable, forming first an aquated halo species and eventually the corresponding aqua hydroxo polymer (Cr(H2O)p(OH)(OP(C6H5)2O)2)n:qH2O. They are quite stable thermally and exhibit initial weight loss at 360 and 310C, respectively, by thermogravimetric analysis. The iodo polymer, on the other hand, starts evolving iodine below 100C. The solubility and visible and infrared spectra of these polymers were studied. (Modified author abstract)