Crystal and molecular structures of three trimethylamine-boron halide adducts: (CH 3 ) 3 NBCl 3 , (CH 3 ) 3 NBBr 3 , and (CH 3 ) 3 NBI 3

X-ray diffraction data from single crystals of the trimethylamine complexes of the three boron halides, BCl 3 , BBr 3 , and BI 3 , lead to a P 2 1 / m monoclinic cell containing two molecules for each complex. The unit cell dimensions are a = 6·68(1), b = 10·247(3), c = 6·502(6) Å, β =116·2(1)° (chloro); a = 6·86(1), b = 10·612(4), c = 6·737(6) Å, β = 115·8(1)° (bromo); a = 6·92(2), b = 10·86(1), c = 7·147(6) Å, β = 93·9(1)° (iodo). The structures were solved by three-dimensional sharpened Patterson functions and show only the chloro and bromo compounds to be isomorphous. Refinement of 662,718 and 954 observed reflexions for the chloro, bromo and iodo complexes, respectively, using anisotropic thermal parameters yielded conventional R factors of 0·045, 0·087 and 0·054.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44832/1/10870_2005_Article_BF01201126.pd