High - Resolution ‘ H and llB NMR Studies of 1 , 2 - and 1 , 7 - B

The 70.6.MHz IrB NMR spectrum of 1,2-B,,C,H,z has been assigned by use of labeled derivatives. The assignments are, in order of increasing field, B(9,12), B(8,10), B(4,5,7,! 1) and B(3,6). Resonances in 1,7-B&H,, are due, in order of increasing field, to B(S,12), B(9,10), B(4,6,8,11) and B(2,3). The ‘H NMR spectrum of 1,2-D,-1,2B,,C,H,, in C,D, contains four quartets at -2.7, -2.5. -2.1, and -1.7 ppm due to H(8,10), H(9,12), H(4,5,7,11) and H(3,6), respectively. Confirmation of the assignment was achieved by double-resonance experiments.