Bis(trifluorophosphine)diborane(4)

Diboron(4) Compounds: From Structural Curiosity to Synthetic Workhorse

“…While the parent compound has continued to elude synthetic chemists, the B 2 H 4 molecule has been captured with the use of Lewis bases, such as phosphines and amines. Numerous examples exist in the literature in which adducts of B 2 H 4 have been synthesized by cleavage of larger polyhedral borane complexes. − For example, the bis-phosphine adduct (Ph 3 P) 2 ·B 2 H 4 was originally prepared by the addition of excess triphenylphosphine to (Me 3 N)·B 3 H 7 in benzene at 50 °C . Kodama and co-workers elegantly used these adducts as building blocks for a variety of borane framework expansion reactions to generate higher order polyhedral boranes. − The only other application of these base-stabilized species has been in their use as ligands for transitions metals, where the borane usually coordinates to one metal center using one or two M–H–B interactions. − An interesting exception was the formation of a rare cobalt complex bridged by a nonsubstituted borylene (BH) group, which was isolated by treatment of Co 2 (CO) 8 with a 2-fold excess of (Me 3 P) 2 ·B 2 H 4 (Scheme ).…”

Unsymmetrical cleavage reaction of .mu.-(dimethylamino)-diborane(6)

“…Over a period of 10-20 days, TMPD reacts with excess (µ-( 3)2 ) 2 5 in diethyl ether or monoglyme according to eq 1. The ionic product III is insoluble in either solvent 2(F-Me2N)B2H5 + TMPD (1) and crystallizes as the reaction proceeds. In one experiment in which the reaction was monitored at 1-5-day intervals by boron-11 NMR spectroscopy, the spectra showed only a steadily diminishing (µ-2 ) 2 5 signal and a steadily increasing sharp triplet due to (Me2NBH2)2.…”

Chemical ionization mass spectrometry of selected boron hydrides

“…CH5+ + B5H9 -> CBSH10+ + 2H2 (6) and/or C2H5+ + B3H9 ->-CB5H10+ + CH4 (7) The dominant ion in the chemical ionization spectrum of C4Hio at source pressures employed in this study is C4H9+. This ion does not protonate B5H9 (see Table I).…”