Isoselenocyanatoborate - Kristallstrukturen von (/i-Bu4N)[BH(NCSe)3] und (Ph4P)[B3H7(NCSe)] Isoselenocyanatoborates - Crystal Structures of (n-Bu4N)[BH(NCSe)3] and (Ph4P)[B3H7(NCSe)]

The treatment of [B6 H6]2with an excess of (SCN )2 in dichloromethane in the presence of solid KOH gives the hexaisoselenocyanatodiborate anion [B2(NCSe)6]2~ as an intermediate (<$(11B) = -10.3 ppm), from which [BH(NCSe)3] “ and elemental selenium are formed. The X-ray structure determinations on single crystals of (rc-Bu4N)2[BH(NCSe)3] (1) (triclinic, space group P i with a = 8.512(2), b = 10.885(3), c = 14.895(4) Ä, a = 79.52(2), ß = 74.86(2), 7 = 86.768(2)°, Z = 2) and (Ph4P)[B3H7(NCSe)] (2) (monoclinic, space group C2, a = 7.686(5), b = 10.366(3), c = 17.533(3) A, ß = 108.89°, Z = 4) show that the selenocyanate groups are coordinated exclusively via the N atoms with average bond lengths of B-N = 1.52, C-N = 1.15, C-Se = 1.75 A and angles N-C-Se = 179°, B-N-C = 168.7 176.8°. The N-B-N angles of 1 range from 107.5 to 109.5°.