. Can. J. Chem. 67, 1644 (1989). The reaction of N,Nf-diethyloxalohydroxamic acid with oxybis(dipheny1borane) yields the title compound. Crystals of 4,8-diethyl-2,2,6,6-tetraphenyl-1,3,5,7-tetraoxa-4,8-diazonia-2,6-diborata-l,2,3,5,6,7-hexahydronaphthalene are monoclinic, a = 14.3405(9), b = 14.3053(5), c = 14.9301(8) 8,, P = 1 16.136(4)", Z = 4, space group P2, / ! I . ' The structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.038 and R , = 0.038 for 3501 reflections with1 2 3u(l). The molecule has a novel bis-six-membered binuclear chelate structure, the Ph'B moieties each being coordinated by (N)O and (C=)O oxygen atoms from different hydroxamate groups. The mean libration-corrected bond distances (C=)&B,

. Can. J. Chem. 68, 69 (1990).Reaction of oxybis(dipheny1borane) with the condensation product of salicylohydroxamic acid and cyclopentanone gives the title compound in good yield. Crystals of 2,2-diphenyl-4,4-tetramethylene-l,3,5-trioxa-3a-azonia-2-borata-2,3,4,5-tetrahydro- Mots cle's : structure cristalline, compost du bore, compost du organobore. IH[Traduit par la revue]

. 66, 2621 (1988).Details of the syntheses, physical properties, and crystal structures of the title compounds are reported. Crystals of 5,5-difluoro-2,2-pentamethylene-1,4,6-trioxa-~a-azonia-5-borata-1,2,3,4,5,6-hexahydrobenzo[l~]azulene are triclinic, a 6.1576(3), b = 11.2651(3), c = 10.81 18(3) A, u = 109.747(3), P = 105.807(4), y = 92.976(4)", Z = 2, space group P 1, and those of 2,2-pentamethylene-5,5-diphenyl-l,4,6-trioxa-30a-azonia-5-borata-1 ,2,3,4,5,6-hexahydrobenzo[h]azulene are monoclinic, a = 9.8549(6), b = 10.9242(6), c = 41.263(2) A, P = 92.7 17(6)", Z = 8, space group P 2 , I n . Both structures were solved by direct methods and were refined by full-matrix least-squares procedures to R = 0.045 and 0.042 for 2344 and 4248 reflections with I 2 3 u ( l ) , respectively. The molecules were both found to possess a seven-membered chelate structure, the 0,0-chelathg ligand being strongly bound to the X2B moiety. Two conformational isomers of the X = Ph compound were found in the solid state. The 2-oxazoline N-oxide moieties present in both compounds are the fi~st to be structurally characterized. [Traduit par la revue]

No abstract

The title compound (III) (space group P21/n, Z=4) has a novel bis‐six‐membered binuclear chelate structure.