USE OF METAL-CARBONYLS IN THE FORMATION OF [H5O2-DOT-15-CROWN-5][MOCL4(H2O)-], (M = MO, W), AND A 2ND SPHERE COORDINATION COMPLEX IN [MER-CRCL3(H2O)(3)CENTER-DOT-15-CROWN-5](CENTER)

The reactions of M(CO)(6) (M = Mo, W) with HCl(g) in the presence of 1 5-crown-5 and H2O in toluene have been explored. These reactions were promoted with the use of UV radiation and formed liquid clathrates alm ost immediately upon reaction. For each metal species, oxidation of th e metal center from either [0] to [ +3] in the case of Cr or from [0] to [+5] in the case of both Mo and W occurred. For chromium, a new iso mer of CrCl3(H2O)(3) was generated in the second-sphere coordination c omplex, [mer-CrCl3(H2O)(3) . 15-crown-5] (1), which crystallized from the liquid clathrate layer in the reaction mixture. For molybdenum and tungsten the isostructural complexes, [H5O2+ . 15-crown-5][MOCl4(H2O) (-)], (M = Mo (2), M = W, (3)) rapidly formed where the H5O2+ oxonium ion was stabilized within the liquid clathrate layer. The structures o f each of these complexes were established by X-ray crystallography. C omplex 1 crystallizes in the monoclinic space group P2(1)/n with a=9.2 61(3), b=16.182(3), c=12.899(5) Angstrom, beta=107.87(1)degrees, V=183 9 Angstrom(3) and D-calc.= 1.568 g cm(-3) for Z=4. Refinement based on 3217 observed reflections led to a final R value of 0.085. Complex 2 crystallizes in the monoclinic space group P2(1)/n with a=12.840(3), b =12.053(1), c=13.290(2) Angstrom, beta=94.26(3)degrees, V=2051 Angstro m(3) and D-calc.=1.720 g cm(-3) for Z=4. Refinement based on 3208 obse rved reflections led to a final R value of 0.051. Complex 3 is isostru ctural with 2 with a=12.805(2), b=12.024(1), c=13.293(2) Angstrom, bet a=94.25(1)degrees, V=2041 Angstrom(3) and D-calc.=2.015 g cm(-3) for Z =4. Refinement based on 2543 observed reflections led to a final R val ue of 0.045. (C) 1998 Elsevier Science S.A. All rights reserved.