Ligand properties of phosphinito platinum complexes: 31P and 195Pt nuclear magnetic resonance studies and the crystal and molecular structure of [Cl(Et3P)Pt(μ-PPh2O)2Pt(PEt3)2][BF4]

1986 ◽  
Vol 64 (9) ◽  
pp. 1903-1911 ◽  
Author(s):  
David Eric Berry ◽  
Kathryn Anne Beveridge ◽  
Jane Browning ◽  
Gordon William Bushnell ◽  
Keith Roger Dixon

Reaction of sodium hydride in tetrahydrofuran with the hydrogen-bonded phosphinito complex, [PtCl(PEt3){(PPh2O)2H}], gives a solution of the salt, [PtCl(PEt3){(PPh2O)2Na}], which is a precusor to synthesis of other bimetallic derivatives, [PtCl(PEt3){(μ-PPh2O)2Q}]n+: n = 0, Q = Rh(COD) or Ir(COD); n = 1, Q = Pd(PEt3)2 or Pt(PEt3)2. Detailed 31P and 195Pt nmr studies are reported for these and related examples including a titanium complex (n = 0, Q = Ti(acac)Cl2) synthesised by direct reaction of [PtCl(PEt3){(PPh2O)2H}] with [TiCl2(acac)2]. The diplatinurn complex, [Cl(PEt3)Pt(μ-PPh2O)2Pt(PEt3)2][BF4] crystallizes in the monoclinic space group P21/n, with a = 13.018(2), b = 34.205(9), c = 11.279(2) Å, β = 91.71(2)°. A complete X-ray diffraction study shows that the two platinum centres are significantly non-planar and are linked by the phosphinito ligands to form a six-membered ring in a boat conformation with phosphorus and oxygen atoms forming the prows of the boat.

1989 ◽  
Vol 67 (1) ◽  
pp. 48-53 ◽  
Author(s):  
David Eric Berry ◽  
Jane Browning ◽  
Gordon William Bushnell ◽  
Keith Roger Dixon ◽  
Alan Pidcock

Reaction of "cyclamphosphorane" (cyclamPH) with [Pt2Cl4(PEt3)2] yields [PtCl(PEt3)(cyclamPH)]Cl. The complex crystallizes as a dichloromethane solvate in the monoclinic space group P21/n, with a = 13.877(3), b = 23.231(7), c = 8.295(2)Å, β = 91.86(4)°, and an X-ray diffraction study shows square planar platinum coordination in which the labile proton of cyclamPH has transferred from phosphorus to nitrogen and the ligand is attached via simple [Formula: see text] chelation. The phosphorus is trans to chlorine in the platinum coordination plane.The corresponding product, trans-[PtCl2(PEt3)(cyclenPH2)]Cl, derived from reaction of "cyclenphosphorane" (cyclenPH) with [Pt2Cl4(PEt3)2], is shown by NMR studies to have a quite different structure in which the ligand is protonated at two nitrogen sites but not at phosphorus. The phosphorus is pentacoordinate with four attachments to nitrogen atoms and one to platinum. The two chlorine atoms are mutually trans in the platinum coordination plane. Keywords: crystal structure, cyclenphosphorane reaction, cyclamphosphorane reaction, X-ray diffraction.


1991 ◽  
Vol 46 (12) ◽  
pp. 1699-1705 ◽  
Author(s):  
Jochen Ellermann ◽  
Falk A. Knoch ◽  
Klaus J. Meier

Reaction of [Cu(PPh3)2(NO3)] (1) in acetone with bis(diphenylphosphino)amine (dppa, 2) yields [Cu(dppa)(PPh3)2]+NO3- (3a). [Cu(dppa)(PPh3)2]+PF6- (3b) has been synthesized by metatheses of 3a with NH4PF6. The salt [Cu(dppm)(PPh3)2]+PF6- (5b) has been prepared by an one batch reaction of [Cu(PPh3)2(NO3)] (1), bis(diphenylphosphino)methane (dppm, 4) and NH4PF6 in methanol, because [Cu(dppm)(PPh3)2]+NO3- (5a) could not be isolated by the direct reaction of 1 with 4. The IR, Raman, 31P{1H} NMR, 1H{31Ρ} NMR as well as the conductivity data are reported and discussed together with the X-ray crystal structure of 3a · 1.8 (CH3)2CO. The structure consists of copper atoms coordinated tetrahedrally by two PPh3 ligands and the chelating dppa ligand and features a highly strained four-membered ring. The distorted tetrahedral cations are hydrogen bridged to the nitrate anions. The colourless needles of 3a· 1.8 (CH3)2CO crystallize in the monoclinic space group C 2/c, with the lattice constants a = 4189.2(27); b = 1223.7(8); c = 2717.8(15) pm;β = 113.16(4)°.


1990 ◽  
Vol 43 (12) ◽  
pp. 2083 ◽  
Author(s):  
DC Craig ◽  
VJ James ◽  
JD Stevens

The crystal structure of the title compound (1) has been determined by X-ray diffraction. Crystals of (1) are orthorhombic, space group P21212 with a 11.425(1), b 24.916(1), c 5.8952(3)Ǻ, Z 4. Refinement on 1675 observed reflections measured with Cu Kα radiation converged at R 0.034. The seven- membered ring adopts a boat conformation in which the pseudo plane of symmetry passes through the ring oxygen.


1986 ◽  
Vol 51 (11) ◽  
pp. 2521-2527 ◽  
Author(s):  
Jan Lokaj ◽  
Eleonóra Kellö ◽  
Viktor Kettmann ◽  
Viktor Vrábel ◽  
Vladimír Rattay

The crystal and molecular structure of SnBu2(pmdtc)2 has been solved by X-ray diffraction methods and refined by a block-diagonal least-squares procedure to R = 0.083 for 895 observed reflections. Monoclinic, space group C2, a = 19.893(6), b = 7.773(8), c = 12.947(8) . 10-10 m, β = 129.07(5)°, Z = 2, C20H38N2S4Sn. Measured and calculated densities are Dm = 1.38(2), Dc = 1.36 Mg m-3. Sn atom, placed on the twofold axes, is coordinated with four S atoms in the distances Sn-S 2.966(6) and 2.476(3) . 10-10 m. Coordination polyhedron is a strongly distorted octahedron. Ligand S2CN is planar.


2018 ◽  
Vol 73 (5) ◽  
pp. 337-348 ◽  
Author(s):  
Sandra Schönegger ◽  
Klaus Wurst ◽  
Gunter Heymann ◽  
Andreas Schaur ◽  
Andreas Saxer ◽  
...  

AbstractA new tin(II) borate with the composition SnB8O11(OH)4 was synthesized by a simple hydrothermal process. It crystallizes in the centrosymmetric monoclinic space group P21/n (no. 14) with the lattice parameters a=790.1(1), b=1402.2(2), c=994.8(1) pm, and β=90.40(5)° (Z=4). The new compound SnB8O11(OH)4 is isotypic to PbB8O11(OH)4 and isostructural to BaB8O11(OH)4. The borate layers are built up from fundamental building blocks (FBBs) with the composition [B8O11(OH)4]2−. Four of these FBBs form a nine-membered ring wherein the Sn2+ cations are located. These boron-oxygen layers are further connected by O–H···O hydrogen bond interactions. The characterization of SnB8O11(OH)4 is based on single-crystal X-ray diffraction data, vibrational spectroscopy, DFT calculations, and thermoanalytical investigations including high temperature powder XRD.


Inorganics ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 21 ◽  
Author(s):  
Koushik Saha ◽  
Urminder Kaur ◽  
Rosmita Borthakur ◽  
Sundargopal Ghosh

The thermolysis of arachno-1 [(Cp*Ru)2(B3H8)(CS2H)] in the presence of tellurium powder yielded a series of ruthenium trithia-borinane complexes: [(Cp*Ru)2(η1-S)(η1-CS){(CH2)2S3BH}] 2, [(Cp*Ru)2(η1-S)(η1-CS){(CH2)2S3B(SMe)}] 3, and [(Cp*Ru)2(η1-S)(η1-CS){(CH2)2S3BH}] 4. Compounds 2–4 were considered as ruthenium trithia-borinane complexes, where the central six-membered ring {C2BS3} adopted a boat conformation. Compounds 2–4 were similar to our recently reported ruthenium diborinane complex [(Cp*Ru){(η2-SCHS)CH2S2(BH2)2}]. Unlike diborinane, where the central six-membered ring {CB2S3} adopted a chair conformation, compounds 2–4 adopted a boat conformation. In an attempt to convert arachno-1 into a closo or nido cluster, we pyrolyzed it in toluene. Interestingly, the reaction led to the isolation of a capped butterfly cluster, [(Cp*Ru)2(B3H5)(CS2H2)] 5. All the compounds were characterized by 1H, 11B{1H}, and 13C{1H} NMR spectroscopy and mass spectrometry. The molecular structures of complexes 2, 3, and 5 were also determined by single-crystal X-ray diffraction analysis.


1975 ◽  
Vol 53 (18) ◽  
pp. 2707-2713 ◽  
Author(s):  
Debbie Allen ◽  
Colin James Lyne Lock ◽  
Graham Turner ◽  
John Powell

The crystal and molecular structures of pentane-2,4-dionato-(2,3,5,6-tetrahapto-2,3-dicarbomethoxo[2.2.1]bicycloheptadienerhodium(I), Rh(C5H7O2)(C7H6(CO2CH3)2), have been measured by single crystal X-ray diffraction. The orange crystals are monoclinic, space group P21/c, Z = 4, a = 9.245(4), b = 9.003(4), c = 21.680(15) Å, β = 113.41(5)°. The calculated and observed densities are 1.645 and 1.642(5) respectively. Intensity data were collected on a Syntex [Formula: see text] diffractometer and a full matrix least squares refinement on 3010 observed reflections leads to a conventional R = 0.0660. The structure can be considered as a roughly square planar arrangement of ligands around the rhodium atom composed of two β-ketoenolate oxygen atoms (Rh—O, 2.037(5) and 2.025(5) Å ) and the centers of the two ethylenic groups. The Rh—C distances for the olefin group attached to the two carbomethoxo groups, 2.117(8), 2.108(8) Å, appear to be slightly larger than those for the other olefinic group, 2.087(7), 2.082(6), and the corresponding C=C distances of 1.375(10) and 1.410(9) Å are different at the 95% confidence level.


1975 ◽  
Vol 53 (22) ◽  
pp. 3383-3387 ◽  
Author(s):  
Joseph Hubert ◽  
André L. Beauchamp ◽  
Roland Rivest

The crystal and molecular structure of dithiocyanato(triphenylarsine)mercury(II) has been determined from X-ray diffraction data. The crystals are monoclinic, space group P21/c, with a = 10.290(7), b = 21.199(23), c = 10.719(7) Å, β = 112.00(2)°, and Z = 4. The structure has been solved by the heavy-atom method and refined by block-diagonal least-squares calculations. The agreement factor R obtained for 2607 'observed' reflections is 0.030. The crystal consists of single molecules. The 'characteristic' coordination number of mercury is three, with two sulfur and one arsenic atoms at the apexes of a triangle. The nitrogen atoms of the thiocyanate groups are at 2.67 and 2.74 Å from the adjoining mercury atoms and therefore link the different molecules together.


1979 ◽  
Vol 57 (2) ◽  
pp. 174-179 ◽  
Author(s):  
A. Wallace Cordes ◽  
Paul F. Schubert ◽  
Richard T. Oakley

The crystal structure of 1,4-diphenyl-2,2′,3,3′,5,5′,6,6′-octamethylcyclo-1,4-diphospha-2,3,5,6-tetrasilahexane, (PhPSi2Me4)2, has been determined by single crystal X-ray diffraction. The crystals are monoclinic, space group P21/c, with a = 9.866(1), b = 11.921(1), and c = 11.324(2) Å, β = 104.31(1)°, Z = 2, and ρcalcd = 1.15 g/cm3. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to a final R of 0.060 and Rw of 0.078, for 1173 reflections with intensities greater than 3σ. The (PhPSi2Me4)2 molecule lies on a crystallographic centre of symmetry, and the six-membered P2Si4 ring has a chair conformation with equatorial phenyl groups. The endocyclic angles at P (104.4(1)°) and Si (104.9(2)°) are intermediate between those found in cyclic hexaphosphine and hexasilane molecules, and the Si—Si and P—Si distances of 2.345(3) and 2.252(4) Å, respectively, correspond to single bond lengths, with no appreciable evidence for secondary pπ → dπ bonding between phosphorus and silicon. The Si—C (1.867(8) Å) and P—C (1.828(7) Å) bond lengths are also normal. The variations in the Si—P—C (101.6(2)°, 108.6(2)°), P—Si—C (range 106.2(3)–120.0(3)°), and Si—Si—C (range 105.8(3)–113.7(3)°) angles indicate that the positions of the exocyclic methyl and phenyl groups are influenced by both intra- and intermolecular steric forces.


1987 ◽  
Vol 42 (4) ◽  
pp. 395-409 ◽  
Author(s):  
Peter Hofmann ◽  
Helmut Heiß ◽  
Gerhard Müller

Based upon the experimentally known but yet unexplained very different reactivities of the two isoelectronic and isolobal intermediates Pt(PMe3)2 and Pt(PEt3)2, the electronic structure and bonding capability of such 14 electron fragments as a function of their geometry (P-Pt-P angle α, determined by the phosphane cone angle) are investigated using molecular orbital calculations. A decrease of the P-Pt -P angle leads to an exceptionally pronounced energy ascent of the b2-HOMO of Pt(PR3)2 species, which, as a consequence, might lead to unusual reactivity patterns and bonding capabilities of 1,3-diphosphaplatinacyclobutane fragments, for which an extreme electronic situation is enforced by steric constraints. Dichloro[η2-bis(di-r-butylphosphino) methane]platinum(II), Pt(dtbpm)Cl2, is synthesized as a potential precursor of Pt(dtbpm), in order to allow experimental investigations of this taylor made four-membered ring chelate complex of Pt(0). The crystal and molecular structure of Pt(dtbpm)Cl2 · 2 CHCl3 has been determined by X-ray diffraction.


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