The crystal and molecular structure of the coordinatively unsaturated Ni(0) species Ni(PPh3)3

1990 ◽  
Vol 68 (4) ◽  
pp. 628-632 ◽  
Author(s):  
David G. Dick ◽  
Douglas W. Stephan ◽  
Charles F. Campana
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Coordination Sphere ◽  
Crystal And Molecular Structure ◽  
Close Approach ◽  
Structural Data ◽  
Triclinic Space Group ◽  
Full Matrix ◽  
Independent Molecules ◽  
Phosphine Complex

The disproportionation of the complex (Et2N)3Ti(μ-PCy2)Ni(PPh3) affords the coordinatively unsaturated species Ni(PPh3)3, 1. This compound crystallizes in the triclinic space group [Formula: see text], with a = 18.483(4) Å, b = 16.203(3) Å, c = 17.783(4) Å, α = 105.85(2)°, β = 117.33(3)°, γ = 92.33(3)°, Z = 4, and V = 4464(2) Å3. Full-matrix least-squares refinement of 1042 variables using 6484 data (Fo2 > 3σFo2) gave R = 0.0441 and Rw = 0.0438. The two crystallographically independent molecules are essentially identical, each exhibiting a trigonal planar coordination sphere at Ni. The most interesting feature of the structure is the close approach (2.744–3.094 Å) of three ortho hydrogens of the PPh3 groups to the Ni centres. The implications of the structural data regarding ortho metallation and the known instability of 1 are discussed. Keywords: coordinatively unsaturated, nickel phosphine complex.

The crystal and molecular structure of anti-1,2,4,5-tetraphenyl-3,6-dicarbomethoxytricyclo[3.1.0.02,4]hexane

1978 ◽  
Vol 56 (10) ◽  
pp. 1364-1367 ◽  
Author(s):  
M. J. Bennett ◽  
J. T. Purdham
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Experimental Error ◽  
Crystal And Molecular Structure ◽  
Structural Data ◽  
Monoclinic Space Group ◽  
Full Matrix ◽  
Bond Lengths ◽  
Highly Strained ◽  
Least Squares Techniques

1,2,4,5-Tetraphenyl-3,6-dicarbornethoxytricyclo[3.1.0.02,4]hexane crystallizes in the monoclinic space group P21/c with a = 10.044(4), b = 9.500(2), c = 14.172(4) Å, β = 104.38(2)°, and Z = 2. Using 1032 unique reflections with I > 3σ(I), the structural data were refined by full matrix least-squares techniques to R = 0.038. The molecule was found to be in the anti-configuration. All bond lengths within the highly strained central tricyclic framework were equal within experimental error and average 1.531 Å.

The preparation of thiolato bridged platinum dimers; the crystal and molecular structure of cis-μμ′-bis(phenylmethanethiolato)bis(phenylmethanethiolatomethyldiphenylphos- phineplatinum(II)), cis-[(PMePh2)Pt(SCH2Ph)(μ-SCH2Ph)]2

1982 ◽  
Vol 60 (16) ◽  
pp. 2075-2081 ◽  
Author(s):  
Peter H. Bird ◽  
Upali Siriwardane ◽  
Rabin D. Lai ◽  
Alan Shaver
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Dihedral Angle ◽  
Crystal And Molecular Structure ◽  
Three Dimensional ◽  
Triclinic Space Group ◽  
Full Matrix ◽  
X Ray ◽  
A Cell ◽  
Facile Route

Fusion invacuo of complexes of the type P2Pt(SR)2 is a facile route to dimers of the type [PPt(SR)(μ-SR)]2; thus, the compounds cis-P2Pt(SR)2, where P = PPh3, PMePh2, R = CH2Ph and trans-P2Pt(SR)2, where P = PPh3, PMePh2, PMe2Ph, R = 4-C6H4CH3 gave the appropriate dimers 1–5. A three-dimensional X-ray structure analysis of the complex [(PMePh2)Pt(SCH2Ph)(μ-SCH2Ph)]2, 2, has shown that it has cis geometry with the benzyl groups of the bridging thiolato ligands oriented anti with respect to each other. The dihedral angle between the two square planes is 138.8°. Crystals of 2 are triclinic, space group [Formula: see text], with two molecules in a cell of dimensions a = 10.856(3) Å, b = 19.935(5) Å, c = 12.202(4) Å, α = 82.52(2)°, β = 105.18(2)°, and γ = 92.35(2)°. Full-matrix least-squares refinement converged at R = 0.052.

Crystal and molecular structure of fac-[dimethylbis(1-pyrazolyl)gallato-N,N′]-(triphenylphosphine)tricarbonylrhenium(I)

1985 ◽  
Vol 63 (3) ◽  
pp. 703-707 ◽  
Author(s):  
Brenda M. Louie ◽  
Steven J. Rettig ◽  
Alan Storr ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths ◽  
Independent Molecules ◽  
Twisted Boat ◽  
Chelate Rings

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.

Crystal and molecular structure of 2,6-dimethyl-3,5-di[N-methyl]carbamoyl-4-[3,4-methoxy]phenyl-l,4-dihydropyridine hemihydrate and 2,6-dimethyl-3,5-di[N-methyl]carbamoyl-4-[furan]1,4-dihydropyridine

1999 ◽  
Vol 214 (12) ◽  
Author(s):  
M. Bidya Sagar ◽  
K. Ravikumar ◽  
Y. S. Sadanandam
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Crystal Structures ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Asymmetric Unit ◽  
Full Matrix

AbstractThe crystal structures of two dihydropyridines were solved by direct methods and refined by full-matrix least-squares procedure. 2,6-Dimethyl-3,5-di[N-methyl]-carbamoyl-4-[3,4-methoxy]phenyl-1,4-dihydropyridine hemihydrate, CBoth compounds crystallize with two molecules in the asymmetric unit. In compound

Crystal and molecular structure of [dimethyl(3,5-dimethyl-1-pyrazolyl)(ethanol-amino)gallato (N(2),O,N(3))](η3-cycloheptatrienyl)dicarbonylmolybdenum

1981 ◽  
Vol 59 (11) ◽  
pp. 1665-1670 ◽  
Author(s):  
Kenneth S. Chong ◽  
Steven J. Rettig ◽  
Alan Storr ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Amino Nitrogen ◽  
Full Matrix ◽  
Octahedral Environment ◽  
Distorted Octahedral ◽  
Unusual Type

Crystals of [dimethyl(3,5-dimethyl-l-pyrazolyl)(ethanolamino)gallato(N(2),O,N(3))](η3-cycloheptatrienyl)dicarbonylmolybdenum are monoclinic, a = 10.511(1), b = 8.335(1), c = 24.138(3) Å, β = 102.22(1)°, Z = 4, space group P21/c. The structure was solved by Patterson and Fourier syntheses and was reflned by full-matrix least-squares procedures to R = 0.028 and Rw = 0.046 for 3708 reflections with I ≥ 3σ(I). The crystal structure consists of discrete molecules linked by N—H … O hydrogen bonds (N … O = 2.929(5) Å). The Mo atom is in a distorted octahedral environment with the η3-C7H7 ligand occupying one coordination site, trans to the amino nitrogen, as a π-donating ligand. Important bond distances (corrected for libration) are: Mo—O, 2.245(2), Mo—N(amino), 2.249(3), Mo—N(pyrazolyl), 2.270(3), Mo—C(O), 1.950(4) and 1.947(4), Mo—C(C7H7), 2.176(4), 2.364(4), and 2.380(4), Ga—O, 1.919(3), Ga—N, 1.984(3), and Ga—C, 1.982(5) and 1.983(5) Å. An unusual type of disorder is present in which a second image of the molecule, approximately mirrored by the plane y = 1/4, is in evidence at low occupancy.

Reaction of N,N′-dihydroxy-.N,N′-dimethylmethanediamine with phenylboronic acid and the crystal and molecular structure of N,N′-dihydroxy-N,N′-dimethylmethanediamine

1989 ◽  
Vol 67 (11) ◽  
pp. 1959-1963 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Phenylboronic Acid ◽  
Direct Methods ◽  
Exact Formula ◽  
Full Matrix ◽  
Space Group ◽  
Hydrogen Bonded

The reaction of N,N′-dihydroxy-N,N′-dimethylmethanediamine with phenylboronic acid leads to the product 1,7-dimethyl-3,5-diphenyl-2,4,6-trioxa-7-aza-1-azonia-3-bora-5-boratabicyclo[3.3.0]octane rather than the expected product 1,5-dimethyl-3-phenyl-1,5-diaza-2,4-dioxa-3-boracyclohexane. The structure of N,N′-dihydroxy-N,N′-dimethylmethanediamine has been determined and is discussed in terms of its reaction with PhB(OH)2. Crystals of N,N′-dihydroxy-N,N′-dimethylmethanediamine are tetragonal, a = 8.5346(3), c = 8.4178(7) Å, Z = 4, space group P421c. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to a final R of 0.036 and Rw of 0.038 for 333 reflections with I ≥ 3σ(I). The structure consists of hydrogen-bonded dimers having exact [Formula: see text] symmetry. Keywords: N,N′-dihydroxy-N,N′-dimethylmethanediamine, crystal structure.

Crystal and molecular structure of 3-ethyl-4-hydroxy-1,2,3(4H)-benzotriazine and 6-chloro-4-hydroxy-3-methyl-4-phenyl-1,2,3-benzotriazine

1985 ◽  
Vol 63 (3) ◽  
pp. 581-585 ◽  
Author(s):  
Kwong Khee Lai ◽  
Carl H. Schwalbe ◽  
Keith Vaughan ◽  
Ronald J. Lafrance ◽  
Clive D. Whiston
Keyword(s):  
Molecular Structure ◽  
Hydrogen Bonds ◽  
Least Squares ◽  
Least Squares Method ◽  
Crystal And Molecular Structure ◽  
Tetrahedral Geometry ◽  
Orthorhombic System ◽  
Full Matrix ◽  
X Ray ◽  
R Factor

The crystal structures of the title compounds have been determined from X-ray data collected on a four-circle diffractometer and refined by the full-matrix least-squares method. The former compound crystallizes in the orthorhombic system, space group Pbcn, with a = 14.346(8), b = 7.239(1), c = 17.276(2) Å, and has been refined to a conventional R factor of 0.043 for 890 observed reflections. Corresponding results for the latter compound are monoclinic, P21/n, a = 12.222(4), b = 7.482(2), c = 14.170(8) Å, β = 94.06(4)°, R = 0.060 for 2128 observed data. The triazine rings of both compounds exhibit short N(1)—N(2) bonds and tetrahedral geometry at C(4); however, the ring is puckered in the first compound but flat in the second. Molecules in both crystals are linked by [Formula: see text] hydrogen bonds.

Crystal and molecular structure of difluoroboron N-methylacethydroxamate (2,2-difluoro-4,5-dimethyl-1,3-dioxa-4-azonia-2-boranatacyclopent-4-ene)

1977 ◽  
Vol 55 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Steven J. Rettig ◽  
James Trotter ◽  
W. Kliegel ◽  
D. Nanninga
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths

Crystals of difluoroboron N-methylacethydroxamate are monoclinic, a = 5.097(1), b = 10.653(2), c = 11.520(2) Å, β = 103.57(2)°, Z = 4, space group P21/c. The structure was solved by direct methods and was refined by full-matrix least squares procedures to a final R of 0.056 and Rw of 0.077 for 988 reflections with I ≥ 3σ(I). The structure features a planar five-membered BO2CN ring. Bond lengths (corrected for libration) are: B—F, 1.374(3) and 1.381(3), O—B, 1.496(3) and 1.497(3), O—N, 1.349(2), O—C, 1.346(2), C—N, 1.298(3) and 1.458(3), and C—C, 1.468(3) Å.

Crystal and Molecular Structure of 2,5-Bis(2′-hydroxyethylamino)-1,4-benzoquinone

1975 ◽  
Vol 53 (5) ◽  
pp. 777-783 ◽  
Author(s):  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Hydrogen Bonds ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Full Matrix ◽  
Space Group ◽  
Compound C ◽  
Related Compounds ◽  
Centrosymmetric Molecule

Crystals of 2,5-bis(2′-hydroxyethylamino)-1,4-benzoquinone are monoclinic, a = 5.020(1), b = 19.238(3), c = 5.214(1) Å, β = 96.15(3)°, Z = 2, space group P21/n. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to a final R of 0.045 for 646 reflections with I ≥ 3σ(I). The benzoquinone ring in the centrosymmetric molecule is slightly, but significantly, nonplanar. Bond distances in the compound (C—C, 1.247 (2) and 1.410 (3), C—N, 1.332 (3) and 1.457 (3), C—C, 1.384–1.514 (3), N—H, 0.89 (3), O—H, 1.07 (5), and C—H, 0.95–1.09 (3) Å) are similar to those in related compounds. The structure features an extensive network of N—H … O (N … O = 2.639 (3) and 3.033 (2) Å) and O—H … O(O … O = 2.757 (3) Å ) hydrogen bonds.

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.

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