CRYSTAL-STRUCTURE OF DI(1-N-DODECYLPYRIDINE) DECAHYDRO-CLOSO-DECABORATE(2-) (C5H5N-C12H25)(2)[B10H10]

Using X-ray analysis, we halle determined the crystal structure of 1-n -dodecylpyridine)decahydrocloso-decaborate(2-), (py-C12H25)2[B10H1O] ( I), a yellow salt-like substance obtained by reaction of (py-C12H25)Br and K-2[B10H10] in an aqueous solution. Compound I melts at 125 degre es without decomposition and luminesces under ultraviolet radiation (l ambda(max) = 555 nm at 298 K). In I, quaternary pyridine bases, contai ning a hydrocarbon radical with the C-12 chain, are combined with the close-cluster hydroborate anion [B10H10](2-). This results in a charge transfer structure having shortened nonvalent (equatorial B) H...H(C of pyridine) contacts of 2.41(8) Angstrom. Crystals I are orthorhombic with a = 8.584(1), b = 7.739(1), c = 31.183(5) degrees V-cell = 2071. 4(5) Angstrom(3), space group Pnmm, Z = 2 d(calc) = 0.986 g/cm(3) (a S yntex P2(1) automatic diffractometer, lambda CuKalpha, N-msd/used = 16 54/711, R(aniso) = 0.076, R(w) = 0.084 w = 1\(sigma(F-obs)(2) + 0.0007 .F-obs(2)). Substantial changes are observed in the vibration range of the valent B-H bonds in the IR spectrum of I as compared to that of p ure ionic K-2[B10H10], confirming the interaction.