Structural, magnetic, and spectroscopic studies of tetrakis(pyridine) complexes of iron(II) sulfonates

1986 ◽  
Vol 64 (3) ◽  
pp. 429-441 ◽  
Author(s):  
John S. Haynes ◽  
Steven J. Rettig ◽  
John R. Sams ◽  
Robert C. Thompson ◽  
James Trotter
Keyword(s):  
Magnetic Susceptibility ◽  
Least Squares ◽  
Ground State ◽  
Heavy Atom ◽  
Spectroscopic Studies ◽  
Zero Field ◽  
Zero Field Splitting ◽  
Scanning Calorimetry ◽  
Full Matrix ◽  
Space Group

The iron(II) complexes Fe(NC5H5)4(RSO3)2 where R = CF3, CH3, and p-CH3C6H4 have been prepared and their crystal structures determined by single crystal X-ray diffraction. Crystals of trans-bis(methanesulfonato-O)tetrakis(pyridine)iron(II) are monoclinic, a = 16.524(2), b = 9.1127(6), c = 18.684(2) Å, β = 109.903(6)°, Z = 4, space group Pn. The structure was solved by conventional heavy-atom methods and was refined by full-matrix least-squares procedures to R = 0.034 and Rw = 0.038 for 4243 reflections with I ≥ 3α(I). Crystals of trans-bis(trifluoromethanesulfonato-O)tetrakis(pyridine)iron(II) are monoclinic, a = 10.456(1), b = 9.2981(8), c = 14.625(2) Å, β = 96.372(6)°, Z = 2, space group Pn. Structure solved and refined as above to R = 0.036, and Rw = 0.037 for 1483 reflections with I ≥ 3σ(I). Crystals of trans-bis(p-toluenesulfonato-O)tetrakis(pyridine)iron(II)are orthorhombic, a = 40.818(2), b = 9.8722(6), c = 17.3544(7) Å, Z = 8, space group Fdd2. The structure was solved by Patterson and Fourier syntheses and was refined by full-matrix least-squares procedures to R = 0.030 and Rw = 0.032 for 1851 reflections with I ≥ 3σ(I). All three structures show discrete octahedral molecules with monodentate trans-coordinated sulfonate groups. Two crystallographically independent molecules are observed in the R = CH3 structure, the difference between them involving the orientation of the CH3SO3 groups with respect to the O—Fe—O vector. The FeN4O2 chromophore in each compound is a tetragonally compressed octahedron (approximate D4h, symmetry) with average Fe—N distances of 2.21, 2.23, and 2.24 Å and Fe—O distances of 2.11, 2.06, and 2.08 Å for theCF3, CH3, and p-CH3C6H4 derivatives, respectively. The compounds were studied using vibrational, electronic, and Mössbauer spectroscopic methods, magnetic susceptibility measurements, and differential scanning calorimetry. Quadrupole splitting values from Mössbauer spectra indicate a 5B2g ground state for all three compounds and magnetic susceptibility data (310–4.2 K) have been analyzed assuming this ground state, using both a crystal field and a zero-field splitting model.

Crystal and molecular structure of [dimethyl(1-pyrazolyl)(2-pyridyl-methoxy)gallato-N2,O,N3](η3-allyl)dicarbonylinolybdenum(II)

1988 ◽  
Vol 66 (3) ◽  
pp. 355-358 ◽  
Author(s):  
Steven J. Rettig ◽  
Alan Storr ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Nitrogen Atom ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Coordination Geometry ◽  
Pyridyl Nitrogen ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths

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.

Crystal and molecular structure of an unusual unsymmetrical isomer of 1,2-Os3(CO)10{P(C6H5)[(η-C5H4)Fe(η-C5H5)]2}2

1992 ◽  
Vol 70 (9) ◽  
pp. 2329-2334 ◽  
Author(s):  
William R. Cullen ◽  
Steven J. Rettig ◽  
Tu Cai Zheng
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Full Matrix ◽  
Space Group

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).

Preparation and characterization of the osmium cluster complexes H2Os3(CO)8L(EtFcPCMe) (L = CO or PEt2Fc) and H2Os3(CO)8[(η-C5H3PEt2)Fe(η-C5H4)]

1993 ◽  
Vol 71 (3) ◽  
pp. 399-409 ◽  
Author(s):  
William R. Cullen ◽  
Steven J. Rettig ◽  
Tu Cai Zheng
Keyword(s):  
Least Squares ◽  
Heavy Atom ◽  
Molar Ratio ◽  
Asymmetric Unit ◽  
Full Matrix ◽  
Space Group ◽  
Cluster Complexes ◽  
Unit Space

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.

Zinc 3,5-dimethylpyrazolate complexes: synthesis and structural studies. The crystal and molecular structure of [Zn2(dmpz)4(Hdmpz)2]

1990 ◽  
Vol 68 (9) ◽  
pp. 1494-1498 ◽  
Author(s):  
Martin K. Ehlert ◽  
Steven J. Rettig ◽  
Alan Storr ◽  
Robert C. Thompson ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
High Yield ◽  
Coordination Geometry ◽  
Structural Studies ◽  
Full Matrix ◽  
Space Group

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.

Reactions of nitriles with binuclear rhodium hydrides. The stepwise reduction of a carbon–nitrogen triple bond at two metal centres

1992 ◽  
Vol 70 (9) ◽  
pp. 2381-2389 ◽  
Author(s):  
Michael D. Fryzuk ◽  
Warren E. Piers ◽  
Steven J. Rettig
Keyword(s):  
Least Squares ◽  
Triple Bond ◽  
Heavy Atom ◽  
Full Matrix ◽  
Space Group ◽  
X Ray ◽  
Hydride Complexes ◽  
Stepwise Reduction ◽  
Rhodium Hydrides

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).

Synthesis and characterization of LMo(CO)3M(PPh3)x (where L = tridentate pyrazolyl-gallate or -borate ligand; M = Rh, x = 2; M = Cu, x = 1). X-ray crystal structures of [MeGapz3]Mo(CO)3Rh(PPh3)2 and [MeGapz3]Mo(CO)3Cu(PPh3) (where pz = pyrazolyl, N2C3H3)

1986 ◽  
Vol 64 (2) ◽  
pp. 373-386 ◽  
Author(s):  
Gregory A. Banta ◽  
Brenda M. Louie ◽  
Emmanuel Onyiriuka ◽  
Steven J. Rettig ◽  
Alan Storr
Keyword(s):  
Least Squares ◽  
Crystal Structures ◽  
Heavy Atom ◽  
Synthesis And Characterization ◽  
Octahedral Structure ◽  
Full Matrix ◽  
Space Group ◽  
X Ray

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.

Catalytic decarbonylation of aldehydes using iron(II) porphyrin complexes, and the crystal structure of (5,10,15,20-tetraphenylporphinato)bis(tri-n-butylphosphine)iron(II)

1988 ◽  
Vol 66 (8) ◽  
pp. 2072-2078 ◽  
Author(s):  
Ramesh M. Belani ◽  
Brian R. James ◽  
David Dolphin ◽  
Steven J. Rettig
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Hydrogen Abstraction ◽  
Heavy Atom ◽  
Crystal Form ◽  
Coordination Geometry ◽  
Full Matrix ◽  
Space Group ◽  
Initiation Reaction ◽  
Trace Water

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.

Pyrazagaboles, pyrazolyl-bridged heterocycles containing boron and gallium

1990 ◽  
Vol 68 (1) ◽  
pp. 59-63 ◽  
Author(s):  
Steven J. Rettig ◽  
Mark Sandercock ◽  
Alan Storr ◽  
James Trotter
Keyword(s):  
Least Squares ◽  
Crystal Structures ◽  
Structural Characterization ◽  
Heavy Atom ◽  
Full Matrix ◽  
Space Group ◽  
The Mean

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.

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