New hydrogen-containing zirconium clusters with phosphine ligands

Reaction of ZrCl4 with 2 equiv. of HSnBu3 followed by addition of phosphines yields hexazirconium cluster compounds [Zr6Cl14H4(PR3)(4)] (2a: PR3 = PMe2Ph; 2b: PR3 = PEt2Ph; 2c: PR3 = PEt3) and pentazirconium cluster compounds [Zr5Cl12H4(PR3)(5)] (3a: PR3 = PMe2Ph; 3c: PR3 = PEt3). Treatment of compound 2a with Na/Hg in the presence of PMe2Ph results in the formation of [Zr6Cl12H2(PMe2Ph)(6)] (4a). When the phosphine ligand is PEt,, a similar reaction leads to the isolation of two new cluster compounds, [Zr6Cl12H3(PEt3)(6)][ZrCl5(PEt3)] (5c) and [Zr6Cl13H3(PEt3)(5)] (6c). In MeCN solution, compound 2a decomposes to form an ionic cluster compound, [HPMe2Ph](4)[Zr6Cl18H4] (7a). Cluster hydrogen atoms were observed by H-1 NMR spectroscopy for all cluster compounds and by X-ray diffraction study for compound 3c where two hydrogen atoms are mu(3)-bridging and the other two edge-bridging. In compound 7a, there is evidence for the four hydrogen atoms distributed near the centers of the eight triangular faces of the Zr, octahedron. When ZrCl4 reacts with 1 equiv. of HSnBu3 followed by addition of PR2Ph, only dinuclear compounds [Zr2Cl4(mu-Cl)(2)(PR2Ph)(4)] (8a: R= Me; 8b: R=Et) are isolated. All compounds were characterized by X-ray crystallography and H-1 NMR spectroscopy. Compound 2a . 0.75CH(2)Cl(2) crystallized in the monoclinic space group C2/c with cell dimensions (-100 degrees C) of a=31.434(9), b=15.255(6), c=14.582(8) Angstrom, beta=106.08(2)degrees, V= 6719(9) Angstrom(3) and Z=4. Compound 2b . 2CH(2)Cl(2) crystallized in the monoclinic space group P2(1)/c with cell dimensions (-60 degrees C) of a = 11.310(1), b = 17.412(5), c = 17.807(2) Angstrom, beta = 91.55(1)degrees, V= 3505(1) Angstrom(3) and Z= 2. Compound 2c . 2C(6)H(6) crystallized in the monoclinic space group P2(1)/n with cell dimensions (- 150 degrees C) of a = 15.322(6), b = 12.186(3), c = 16.696(7) Angstrom, beta = 91.09(2)degrees, V= 3117(2) Angstrom(3) and Z= 2. Compound 2e crystallized in the monoclinic space group C2/e with cell dimensions ( - 150 degrees C) of a = 26.128(9), b = 16.826(1), c = 13.411(4) Angstrom, beta = 117.07(1)degrees, V= 5250(2) Angstrom(3) and Z=4. Compound 3e . C6H5CH3 crystallized in the monoclinic space group C2/c with cell dimensions (- 75 degrees C) of a = 48.06( 1), b = 12.667(3), c = 22.829(5) Angstrom, beta = 113.36(2)degrees, V= 12758(5) Angstrom(3) and Z= 8. Compound 4a crystallized in the triclinic space group P (1) over bar with cell dimensions (- 60 degrees C) of a = 12.918(3), b = 15.493(2), c = 18.90(1) Angstrom, alpha = 90.31 (6), beta = 104.37(2), gamma = 109.89(3)degrees, V= 3429(2) Angstrom(3) and Z= 2. Compound 5c . 0.5C(6)H(6) crystallized in the monoclinic space group P2/c with cell dimensions (- 60 degrees C) of a = 23.707(6), b = 14.521(2), c = 25.109(3) Angstrom, beta= 92.08(1)degrees, V= 8633(3) Angstrom(3) and 2=4. Compound 6c . C6H6 crystallized in the orthorhombic space group Pna2(1) with cell dimensions (- 100 degrees C) of a=23.496(9), b=23.973(2), c=11.638(1) Angstrom, V= 6555(3) Angstrom(3) and Z = 4. Compound 7a . 2MeCN crystallized in the triclinic space group P (1) over bar with cell dimensions (20 degrees C) of a = 12.881 (2), b = 22.859(3), c = 12.208(2) Angstrom, alpha = 98.66(1), beta = 109.99(1), gamma = 81.39(1)degrees, V= 3320.8(9) Angstrom(3) and Z= 2. Compound 8b . 0.67C(6)H(5)CH(3) crystallized in the rhombohedral space group R (3) over bar m with cell dimensions (-100 degrees C) of a=20.947(3), b=20.947(3), c=30.87(1) Angstrom, V= 11730(4) Angstrom(3) and Z= 6.