Structural studies of organoboron compounds. XXXIV. 4-(N-Methoxymethylimino)-2,2-diphenyl-1,3-dioxa-2-borata-1,2,3,4-tetrahydronaphthalene and 4-diethylimino-2,2-diphenyl-1,3-dioxa-2-borata-1,2,3,4-tetrahydronaphthalene

Abstract

Details of the syntheses, physical properties, and crystal structures of the title compounds are reported. Crystals of 4-(N-methoxymethylimino)-2,2-diphenyl-1,3-dioxa-2-borata-1,2,3,4-tetrahydronaphthalene, 4, are monoclinic, a = 9.8072(5), b = 9.6217(7), c = 19.6793(12) Å, β = 94.871(5)°, Z = 4, space group P21/c, and those of 4-diethylimino-2,2-diphenyl-1,3-dioxa-2-borata-1,2,3,4-tetrahydronaphthalene, 9, are orthorhombic, a = 17.0593(7), b = 16.1372(6), c = 14.3753(5) Å, Z = 8, space group Pbca. Both structures were solved by direct methods and were refined by full-matrix least-squares procedures to R = 0.046 and 0.038 for 2198 and 2969 reflections with I ≥ 3σ(I), respectively. In both structures the N,N-dialkylsalicylamidate ligands coordinate the diphenylboron moieties via the phenolate oxygen and amide oxygen atoms, forming six-membered O—B—O chelate rings. The O(ar)—B, O(amide)—B, and mean C—B bond lengths (corrected for libration) are as follows: 1.490(3), 1.549(4), and 1.612 Å for 4 and 1.494(2), 1.550(2), and 1.612 Å for 9. Keywords: crystal structures, boron compounds, organoboron compounds.