A Comparative Study on the Structural and Chemical Properties of Group 13–15 Element Addition Compounds t Bu 2 PH·EX 3 (E = B, Al, Ga, In; X = Cl, Br)

The group 13–15 element addition compounds t Bu 2 PH·EX 3 (E = B, Al, Ga, In; X = Cl, Br) are accessible from the reaction of t Bu 2 PH with the triel halides EX 3 (E = B, Al, Ga, In; X = Cl, Br) at room temperature. The crystal structures of the group 13–15 element addition compounds t Bu 2 PH·BBr 3 (monoclinic, P 2 1 / c ) and t Bu 2 PH·EBr 3 (E = B, Al, Ga, In) (monoclinic, P 2 1 / n ) are described. When the addition compound t Bu 2 PH·BBr 3 was treated with one equivalent of LiN(SiMe 3 ) 2 , the reaction led to the formation of the cyclophosphinoborane ( t Bu 2 PBBr 2 ) 2 . The structure of ( t Bu 2 PBBr 2 ) 2 (monoclinic, C 2/ m ) displays a four‐membered P 2 B 2 ring whereas the cyclophosphinoalane (Ph 2 PAlMe 2 ) 3 which was obtained from Ph 2 PH and AlMe 3 has a six‐membered P 3 Al 3 ring structure (monoclinic, P 2 1 / c ). In addition, we report the result of the X‐ray structure analysis of the oxidation product of t Bu 2 PH·BBr 3 , the phosphane oxide adduct t Bu 2 PHO·GaBr 3 (orthorhombic, Pnma ) and of the phosphonium salt [ t Bu 2 PH 2 ] + [GaBr 4 ] – (monoclinic, P 2 1 / n ).