Molybdenum–tin and molybdenum–copper complexes derived from the molybdenum tricarbonyl anions, LMo(CO)3− (where L = HBpz3 or HBpz″3; pz = pyrazolyl, N2C3H3; and pz″ = 3,5-dimethylpyrazolyl, N2C5H7)

1988 ◽  
Vol 66 (8) ◽  
pp. 1997-2006 ◽  
Author(s):  
Yan-Yun Liu ◽  
Arthur Mar ◽  
Steven J. Rettig ◽  
Alan Storr ◽  
James Trotter

The pyrazolylborate molybdenum tricarbonyl anions, (HBpz3)Mo(CO)3− and (HBpz″3)Mo(CO)3−, have been utilized to prepare a number of heteronuclear bimetallic species containing Mo—Sn and Mo—Cu bonds. Crystals of [hydrotris(1-pyrazolyl)borato-N,N,N](triphenylstannyl)tricarbonylmolybdenum are monoclinic, a = 17.570(2), b = 14.077(2), c = 12.180(1) Å, β = 96.985(8)°, Z = 4, space group P21/n, those of [hydrotris(1-3,5-dimethylpyrazolyl)borato-N,N,N](chlorodimethylstannyl)tricarbonylmolybdenum are monoclinic, a = 11.044(3), b = 12.061(2), c = 20.218(4) Å, β = 100.43(1)°, Z = 4, space group P21/c, and those of [hydrotris(1-pyrazolyl)borato-N,N,N]tricarbonylmolybdenum(N,N,N′,N′-tetramethylethylenediamine)copper dichloromethane solvate are orthorhombic, a = 19.027(2), b = 16.995(2), c = 16.136(2) Å, Z = 8, space group Pbca. The structures were solved by conventional heavy atom methods and refined by full-matrix least-squares procedures to R = 0.044, 0.042, and 0.059 for 2084, 2502, and 1891 reflections, respectively. The two tin structures have a 3:3:1 capped octahedral structure with Mo—Sn bonds of 2.864(1) and 2.823(1) Å. The copper complex has a 3:4 piano stool arrangement of ligands about Mo with a Mo—Cu bond of 2.639(2) Å, two semibridging carbonyl ligands, and one terminal carbonyl ligand.


1986 ◽  
Vol 64 (2) ◽  
pp. 373-386 ◽  
Author(s):  
Gregory A. Banta ◽  
Brenda M. Louie ◽  
Emmanuel Onyiriuka ◽  
Steven J. Rettig ◽  
Alan Storr

The reactions of the LMo(CO)3− ions (L = MeGapz3, HBpz3, Me2Gapz(OCH2CH2NMe2)) with [Cu(PPh3)Cl]4 and Rh(PPh3)3Cl have yielded complexes with Mo—Cu and Mo—Rh bonds. The X-ray crystal structures of two such complexes have been determined. Crystals of [MeGapz3]Mo(CO)3Cu(PPh3) are monoclinic, a = 17.071(2), b = 16.738(1), c = 23.641(3) Å, β = 104.899(6)°, Z = 8, space group P21/n, and those of [MeGapz3]Mo(CO)3Rh(PPh3)2, are triclinic, a = 12.519(3), b = 17.182(4), c = 12.071(2) Å, α = 105.02(1), β = 109.87(1), γ = 97.10(2)°, Z = 2, space group [Formula: see text]. Both structures were solved by conventional heavy atom methods and were refined by full-matrix least-squares procedures to R = 0.040 and Rw = 0.035 for 6296 reflections with I ≥ 2σ(I) and R = 0.036 and Rw = 0.037 for 5642 reflections with I ≥ 3σ(I), respectively. The former complex provides a rare example of a 3:3:1, or capped octahedral structure, with a short (mean) Mo—Cu distance of 2.513(9) Å. The latter compound displays one terminal and two bridging CO ligands and a Mo—Rh distance of 2.6066(5) Å.



1988 ◽  
Vol 66 (3) ◽  
pp. 355-358 ◽  
Author(s):  
Steven J. Rettig ◽  
Alan Storr ◽  
James Trotter

Crystals of [dimethyl(1-pyrazolyl)(2-pyridylmethoxy)gallato-N2,O,N3](η3-allyl)dicarbonylmolybdenum(II) are triclinic, a = 9.632(2), b = 9.798(2), c = 10.255(2) Å, α = 80.16(1), β = 87.38(1), γ = 81.75(1)°, Z = 2, space group [Formula: see text]. The structure was solved by conventional heavy-atom methods and was refined by full-matrix least-squares procedures to R = 0.033 and Rw = 0.037 for 3000 reflections with I ≥ 3σ(I). The molecule has pseudo-octahedral coordination geometry with the tridentate [Me2Ga(N2C3H3)(OCH2(C5H4N))]− ligand facially coordinated and the η3-allyl ligand occupying one coordination site trans to the pyridyl nitrogen atom. Important bond lengths are Mo—O = 2.219(2), Mo—N(py) = 2.212(3), Mo—N(pz) = 2.232(2), Mo—C(allyl) = 2.290(4), 2.189(4), 2.341(4), Mo—CO (trans to O) = 1.928(4), and Mo—CO (trans to N) = 1.952(4) Å.



1992 ◽  
Vol 70 (9) ◽  
pp. 2329-2334 ◽  
Author(s):  
William R. Cullen ◽  
Steven J. Rettig ◽  
Tu Cai Zheng

The reaction of Os3(CO)10(MeCN)2 with PFc2Ph (Fc = (η-C5H4)Fe(η-C5H5)) affords the unsymmetrical isomer of 1,2-Os3(CO)10(PFc2Ph)2, 2. Crystals of 2 are monoclinic, a = 27.846(4), b = 11.253(4), c = 38.520(3) Å, β = 107.813(9)°, Z = 8, space group C2/c. The structure was solved by heavy atom methods, and was refined by full-matrix least-squares procedures to R = 0.030 and Rw = 0.027 for 5073 reflections with I ≥ 3σ(I).



1993 ◽  
Vol 71 (3) ◽  
pp. 399-409 ◽  
Author(s):  
William R. Cullen ◽  
Steven J. Rettig ◽  
Tu Cai Zheng

Thermolysis of Os3(CO)11(PEt2Fc) (Fc = (η-C5H4)Fe(η-C5H5)) in octane for 8 h affords H2Os3(CO)9(EtFcPCMe), 10, and H2Os3(CO)8[(η-C5H3PEt2)Fe(η-C5H4)], 9e, in 15 and 65% yield, respectively. Heating Os3(CO)12 and PEt2Fc in 1:2 molar ratio in xylene for 10 h gives two isomers of H2Os3(CO)8(PEt2Fc)(EtFcPCMe), 11, in about 40% yield. Two crystalline modifications of the complex 9e have been obtained from the same solvent: 9eA, triclinic, a = 15.653(1), b = 15.799(1), c = 11.257(1) Å, α = 90.388(7)°, β = 109.740(6)°, γ = 82.445(6)°, Z = 4 (two molecules per asymmetric unit), space group [Formula: see text]; and 9eB, monoclinic, a = 9.889(2), b = 13.632(3), c = 18.927(4) Å, β = 97.36(2)°, Z = 4, space group P21/n. The structures were solved by heavy atom methods and were refined by full-matrix least-squares procedures to R = 0.033 and 0.037 for 8131 and 5145 reflections with I ≥ 3σ(I), respectively.



1990 ◽  
Vol 68 (9) ◽  
pp. 1494-1498 ◽  
Author(s):  
Martin K. Ehlert ◽  
Steven J. Rettig ◽  
Alan Storr ◽  
Robert C. Thompson ◽  
James Trotter

Zinc metal reacts with excess 3,5-dimethylpyrazole (Hdmpz) in the presence of O2 to produce materials of composition Zn(dmpz)2(Hdmpz)y. Thermolysis of these materials results in the loss of Hdmpz and the formation of the [Zn(dmpz)2]x polymer. Under appropriate conditions the pure dimer [Zn2(dmpz)4(Hdmpz)2] can be obtained in high yield. Crystals of bis[μ-(3,5-dimethylpyrazolyl-N1,N2)]bis[(3,5-dimethylpyrazolyl)(3,5-dimethylpyrazole)zinc(II)] are orthorhombic, a = 17.009(2), b = 29.239(2), c = 13.590(2) Å, Z = 8, space group Fddd. The structure was solved by heavy atom methods and was refined by full-matrix least-squares procedures to R = 0.037 and Rw = 0.042 for 913 reflections with I ≥ 3σ(I). The structure of [Zn2(dmpz)4(Hdmpz)2] contains nearly planar doubly dmpz bridged Zn2 units capped at each end by strongly hydrogen-bonded [Formula: see text] units. The zinc atoms display pseudotetrahedral coordination geometry with Zn—N = 1.991(3) (bridging) and 2.025(3) Å (terminal), and N—Zn—N = 99.6(2)–113.8(2)°. Keywords: zinc 3,5-dimethylpyrazolate complexes, crystal structure.



1992 ◽  
Vol 70 (9) ◽  
pp. 2381-2389 ◽  
Author(s):  
Michael D. Fryzuk ◽  
Warren E. Piers ◽  
Steven J. Rettig

The reaction of simple nitriles, R′CN (R′ = CH3, Ph, o-tol) with the electron-rich binuclear rhodium hydride derivatives [(R2PCH2CH2PR2)Rh]2(μ-H)2 (R = Pri: [(dippe) Rh]2(μ-H)2; R = OPri: [(dipope)Rh]2(μ-H)2) results in the formation of alkylideneimido derivatives [(R2PCH2CH2PR2)Rh]2(μ-H)(μ-N=CHR′), apparently by insertion of the nitrile moiety into a bridging hydride bond; this was confirmed by the reaction of nitriles with the dideuteride [(dippe)Rh]2(μ-D)2, which resulted in the formation of [(dippe)Rh]2(μ-D)(μ-N=CHR′). Further reduction can take place by addition of H2 to generate the corresponding amide hydride derivatives [(dippe)Rh]2(μ-H)(μ-NHCH2R′); this represents an overall stoichiometric reduction of a nitrile to a coordinated amide at a binuclear centre. These same amido-hydride complexes can be accessed by addition of amine to the starting binuclear rhodium hydride derivatives. The X-ray structure of [(Pri2PCH2CH2PPri2)Rh]2(μ-H)(μ-N=CHCH3) was undertaken to confirm the structure of these particular intermediates. Crystals of this material are monoclinic, a = 19.036(2), b = 15.139(1), c = 13.604(1) Å, β = 104.119(7)°, Z = 4, space group P21/c. The structure was solved by heavy atom methods and was refined by full-matrix least-squares procedures to R = 0.038 and Rw = 0.041 for 5814 reflections with I ≥ 3σ(I).



1988 ◽  
Vol 66 (8) ◽  
pp. 2072-2078 ◽  
Author(s):  
Ramesh M. Belani ◽  
Brian R. James ◽  
David Dolphin ◽  
Steven J. Rettig

The complex (5, 10, 15, 20-tetraphenylporphinato)bis(tri-n-butylphosphine)iron(II), 1, has been isolated in a triclinic crystal form, a = 12.499(3), b = 12.528(2), c = 12.039(2) Å, α = 116.39(1), β = 109.79(1), γ = 98.13(1)°, Z = 1, space group [Formula: see text]. The structure was solved by conventional heavy atom methods and was refined by full-matrix least-squares procedures to R = 0.060 and Rw = 0.070 for 3551 reflections with I ≥ 3σ(I). The molecule, which has crystallographic [Formula: see text], symmetry, displays a relatively undistorted pseudo-octahedral coordination geometry with Fe—P = 2.346(1) and Fe—N = 1.998(3) and 1.993(3) Å. In CH2Cl2 solution, 1 reacts with CO and aldehydes to generate the carbonyl(phosphine) derivative, and decarbonylation of phenylacetaldehyde to toluene becomes catalytic under an Ar stream. The aldehyde decarbonylations involve radical pathways via carbonyl loss from [Formula: see text]. The hydrogen abstraction/initiation reaction probably utilizes trace O2 (and possibly trace (water); speculative mechanisms are discussed.



1990 ◽  
Vol 68 (1) ◽  
pp. 59-63 ◽  
Author(s):  
Steven J. Rettig ◽  
Mark Sandercock ◽  
Alan Storr ◽  
James Trotter

The synthesis and structural characterization of representative and novel pyrazagaboles, boron- and gallium-containing compounds with a central six-membered heterocyclic B—(N—N)2—Ga ring feature, are detailed. Crystals of dimethylgallium-bis(μ-pyrazolyl)dimethylboron are orthorhombic, a = 7.6135(5), b = 16.2917(5), c = 22.331(1) Å, Z = 8, space group Pbca, and those of hydroxy(methyl)galliumbis(μ-pyrazolyl)dimethylboron are orthorhombic, a = 7.6197(3), b = 16.2184(7), c = 22.190(1) Å, Z = 8, space group Pbca. Both structures were solved by conventional heavy atom methods and were refined by full-matrix least-squares procedures to R = 0.054 and 0.040 for 1243 and 1272 reflections with I ≥ 1.5 and 3σ(I), respectively. The crystal structures are isomorphous and both feature six-membered B—(N—N)2—Ga rings having highly asymmetric boat conformations, unlike those observed for the majority of the homobinuclear analogs previously reported. The mean Ga—N and B—N distances in the two compounds are 1.977 and 1.61 Å. Keywords: pyrazagaboles, pyrazolyl-bridged heterocycles, crystal structures, synthesis of pyrazagaboles.



1987 ◽  
Vol 65 (10) ◽  
pp. 2469-2477 ◽  
Author(s):  
G. D. Gracey ◽  
Steven J. Rettig ◽  
Alan Storr ◽  
James Trotter

The synthesis, characterization, and structures of complexes containing the o-aminophenolato ligand are detailed. A novel molybdenum amidine complex is also described. Crystals of (o-aminophenolato)dimethylgallium are monoclinic, a = 10.1970(9), b = 9.7597(7), c = 18.778(2) Å, β = 100.810(7)°, Z = 8, space group C2/c, those of bis(dimethylgallium-1-pyrazolyl-o-aminophenolato)nickel(II) benzene solvate are monoclinic, a = 20.491(1), b = 11.789(1), c = 15.789(1) Å, β = 103.413(7)°, Z = 4, space group C2/c, and those of η3-allyl(bromo)[2-(1-pyrazolyl)ethylidenarnino]dicarbonylmolybdenum(II) are monoclinic, a = 11.0278(4), b = 8.4461(2), c = 15.3747(5) Å, β = 109.208(3)°, Z = 4, space group P21/c. The structures were solved by conventional heavy atom methods and refined by full-matrix least-squares procedures to R = 0.030, 0.053, and 0.038 for 1980, 1684, and 1901 reflections, respectively. Reaction of the [Me2Ga(pz)(OC6H4NH2)]− ligand, L−, with [Re(CO)4Cl]2 results in the formation of LRe(CO)3 whose physical properties indicate a fac arrangement of the organogallate ligand.



1985 ◽  
Vol 63 (3) ◽  
pp. 703-707 ◽  
Author(s):  
Brenda M. Louie ◽  
Steven J. Rettig ◽  
Alan Storr ◽  
James Trotter

Crystals of fac-[dimethylbis(1-pyrazolyl)gallato-N,N′](triphenylphosphine)tricarbonylrhenium(I) are triclinic, a = 9.479(2), b = 16.258(4), c = 20.412(6) Å, α = 110.06(1), β = 95.46(1), γ = 92.65(2)°, Z = 4, space group [Formula: see text] The structure was solved by conventional heavy-atom methods and was refined by full-matrix least-squares procedures to R = 0.027 and Rw = 0.031 for 5965 reflections with I ≥ 3σ(I). The two crystallographically independent molecules have nearly identical structures. The coordination about Re is distorted fac-octahedral with mean bond lengths: Re—P = 2.538(4), Re—N = 2.201(5), Re—CO(trans to P) = 1.931(1), and Re—CO(trans to N) = 1.913(9) Å. The ReGaN4 chelate rings have twisted boat conformations with cross-ring [Formula: see text] separations of 3.9396(7) and 3.8981(8) Å.



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