Synthesis, Structure And Properties Of Organosilyl Derivatives Of Keggin Trivacant Heteropolyanion

In the presence of Bu4NBr acting as phase-transfer reagent, the reaction of organosilicon trichloride with the trivacant heteropolyanion [α-A-XW₉O₃₄]^n-(X=P, Si, Ge, Ga) sodium salt was carried out in acetonitrile successfully. The complexes have been characterized by elemental analysis,IR and UV spectroscopy,X-ray crystallography,TG methods.(1) Reaction of the trivacant heteropolyanions [α-A-XW₉O₃₄]^n-(X=P, Si, Ge, Ga) with C₆H₅SiCH₃Cl₂ leads to the formation of the organosilyl derivative of the trivacant heteropolyanions. The anions all consists of oneα-A-XW₉(X=P, Si) framework on which are grafted by three C₆H₅SiCH₃ groups through six Si-O-W bridges, and become opened structure. The thermal of two compounds were also studied.(2) We have successfully synthesized a novel six-substituted organosilyl derivative of the trivacant heteropolyanions based on the reaction of the trivacant heteropolyanions Na10[α-SiW₉O₃₄]·18H₂O with CH₃SiHCl₂. The anion consists of oneα-A-SiW₉ framework on which are grafted by six CH₃Si groups through six Si-O-W bridges, six CH₃Si groups are attached to each other through Si-O-Si bridges and become opened structure.(3) Reaction of the trivacant heteropolyanions Na₉[A-PW₉O₃₄]·nH₂O with (CH₃)₂CHCH₂SiCl₃ leads to the formation of the organosilyl derivative of the [A-PW₉O₃₄]^9-. The anion consists of oneα-A-PW₉ framework on which are grafted by three (CH₃)2CHCH2Si groups through six Si-O-W bridges, each of which is attached to the fourth (CH₃)₂CHCH₂Si through three Si-O-Si bridges and become closed structure.