FURTHER INVESTIGATIONS INTO THE SYNTHESIS AND CHARACTERIZATION OF HALO-BORON-ARSENIC COMPOUNDS - X-RAY CRYSTAL-STRUCTURES OF X3B-CENTER-DOT-AS(SIME3)(3) (X = CL, I) AND [I2BAS(SIME3)(2)](2)

A low-temperature ( -78 degrees C) 1:1 mole ratio reaction of BI3 with As(SiMe3)(3) produced the 1:1 Lewis acid-base adduct I3B . As (SiMe3) (3) (1), whereas the identical reaction performed at room temperature (previously reported)(1) produced the dimeric compound, [I2BAs(SiMe3)( 2)](2) (2). Full characterization df compound 1 was conducted, includi ng a single-crystal X-ray structural determination. The previously unr eported X-ray crystal structures of 2 and Cl-3; B . As(SiMe3,)(3) (3) have also been elucidated. Crystals of 1 belong to the orthorhombic sp ace group Pbca, with a = 13.8673(13), b = 17.5885(8), c = 22.8784(22) Angstrom, V = 5580.1(8) Angstrom(3), D-calc = 1.853 g cm(-3) for Z = 8 , and the B-As bond length is 2.104(15) Angstrom. Crystals of 2 belong to group P2(1)/n, with a = 9.836(5), b = 13.682(3), c=11.701(6)Angstr om V = 1545.8 (12) Angstrom(3),:D-calc = 2.088 g cm(-3) for Z = 4, and the average B-As bond length is 2.13 Angstrom. Compound 3 crystallize s in the orthorhombic space group Pbca, with n=13.4109(2), b = 17.1371 (2), c = 21.7996(3) Angstrom, V = 5010.07(12) Angstrom(3): D-calc = 1. 336 g cm(-3) for Z = 8, and the B-As bond length is 2.118(6) Angstrom.