SYNTHESIS AND CHARACTERIZATION OF TRIARYLBORTHIINS, AR3B3S3 (AR = 4-MEC6H4, 3-MEC6H4, 2-MEC6H4, 4-ETC6H4, AND 3,5-ME2C6H3)

The air/moisture-sensitive triarylborthiins, Ar3B3S3 (Ar = 4-MeC6H4, 3 -MeC6H4, 2-MeC6H4, 4-EtC6H4, and 3,5-Me2C6H3), have been prepared by t he reaction of ArBBr2 with HgS in benzene at reflux and have been char acterized by B-11 NMR and IR spectroscopy and mass spectrometry. The s ubstituted aryl derivatives are less air-stable than Ph3B3S3, and in a ir significantly decompose to boron-oxygen species within minutes; the approximate order of air-stability is (Ar=) Ph > 3,5-Me2C6H3 > 4-EtC6 H4 > 4-MeC6H4 > 3-MeC6H4 > 2-MeC6H4. ArBBr2 compounds have been prepar ed by the reaction of ArHgBr with BBr3; their B-11, C-13, and H-1 NMR data are presented. NMR (C-13, H-1) data are also reported for the ArH gBr species prepared by reaction of ArMgBr with HgBr2.