MICROWAVE-SPECTRUM OF TRANS-NITROSOETHYLENE-N-15 AND PYROLYSIS MECHANISM OF CHLOROACETALDEHYDE OXIME

The microwave spectrum of trans-nitrosoethylene-N-15 (nitrosoethene) g enerated by pyrolysis of chloroacetaldehyde oxime-N-15 has been observ ed in the frequency range from 8.0 to 40.0 GHz. The relational constan ts of the N-15 species are determined to be A = 50390(201), B = 5057.0 0(3), and C = 4605.29(3) MHz. The r(s)-coordinates (a and b) of the ni trogen atom of trans-nitrosoethylene are determined to be 0.540(1) and 0.453 Angstrom, respectively. The three r(0) structural parameters we re fitted to four rotational constants (B and C) of the normal and N-1 5 species. The bond length of r(C-N) and two bond angles of[C] = C-N a nd < C-N = O obtained are 1.439(10) Angstrom, 117.1(10)degrees, and 11 2.7(10)degrees, respectively. The possible pyrolysis mechanism of chlo roacetaldehyde oxime was discussed on the basis of detecting the three pyrolysates (CH2 = CH-(NO)-N-15, (HCN)-N-15, and CH2 = O) by microwav e spectroscopy. (C) 1995 Academic Press,Inc.