REACTION OF 1,2-DIPHENYLETHANE WITH D-2

The reaction of 1,2-diphenylethane (DPE) with D-2 (2000 psi) was studi ed at 450 degrees C. The results of GC/MS and NMR analysis of reaction products and of products from reactions of 1,2-diphenylethane-1,1-d(2 ), 1,2-di(phenyl-d(5))ethane, and 1,2,3,4-tetraphenylbutane confirm a mechanistic scheme in which the main process for introduction of D is the reaction of 1,2-diphenylethyl radical with D-2. This reaction, tho ugh energetically uphill, competes with termination processes because of the high concentration of D-2 relative to that of radical species. The reaction generates D atoms which attack aromatic ring positions to give substitution for both H and alkyl substituents. Evidence is prov ided for D and H atom transfer between aliphatic positions in DPE in t he presence of either N-2 or H-2 and between aromatic positions only w hen provoked by H-2 or D-2. Only a small amount of exchange between ar omatic and aliphatic positions is observed under any conditions. The a ttack of D atoms at H-carrying aromatic positions makes H atoms availa ble for transfer to other aromatic positions. The process results in a D-2-provoked generation of benzene-d(0). Mechanistic alternatives for these and other processes are discussed.