Reactions of But-2-yne and Hexafluorobut-2-yne with Dicarbonyl(η-pentamethylcyclopentadienyl)-cobalt, -rhodium and -iridium. Structure of the iridium complex (η-C5Me5)Ir2(CO)2(CF3C2CF3)3H

1978 ◽  
Vol 31 (9) ◽  
pp. 1937 ◽  
Author(s):  
PA Corrigan ◽  
RS Dickson ◽  
GD Fallon ◽  
LJ Michel ◽  
C Mok

The reactions of but-2-yne and hexafluorobut-2-yne with the complexes (η-C5Me5)M(CO)2, M = CO, Rh, or Ir, have been compared. A cyclopentadienone complex, (η-C5Me5)M[C4Me4CO]2 is the major product formed in the reaction of but-2-yne with (η-C5Me5)M(CO)2, M = Co or Rh. The cobalt system also gives some hexamethylbenzene whereas the rhodium system yields the pentadienone-dirhodium complex (q-C5Me5)2Rh2(MeC2Me)2CO. The cyclopentadienone complexes (η-C5Me5)M[C4(CF3)4CO], M = CO and Rh, were major products from the reactions of hexa- fluorobut-2-yne with (η-C5Me5)M(CO)2. Hexakis(trifluoromethyl)benzene and the tetrahapto- benzene complexes (η-C5Me5)M[η4-C6(CF3)6], M = Co or Rh, were minor products from these reactions. Small amounts of the dirhodium complexes (η-C5Me5)2Rh2(CF3C2CF3)2(CO)n, n = 1 or 2, were also isolated from the rhodium system under some reaction conditions. No products could be isolated from the reaction between (η-C5Me5)Ir(CO)2 and but-2-yne, but the reaction with hexafluorobut-2-yne gives two organoiridium complexes. One complex, (η-C5Me5)Ir(CO)2(CF3C2CF3), incorporates an iridiocyclobutenone ring and one terminal carbonyl. The second, (η-Ir5Me5)Ir2(CO)2(CF3C2CF3)3H, has been characterized crystallographically. The compound crystallizes with four molecules in the orthorhombic space group Pnma in a cell of di- mensions a 14.262(5), b 13.293(5), c 15.027(5) Ǻ. The structure has been refined by standard methods to a conventional R factor of 0.072, based on 2061 reflections above background. The environments of the two iridium atoms are markedly different. One forms part of a metallopentadiene ring, and it is also attached to two terminal carbonyls, a σ-bonded C(CF3)=C(CF3)H group, and the other iridium atom [Ir-Ir distance 2.737(1) Ǻ]. Overall, this iridium has a distorted octahedral geometry. The second iridium is n-bonded in a conventional sandwich manner to the C5Me5 and iridiocycle rings; these two rings have a staggered conformation and are close to parallel.

1974 ◽  
Vol 52 (16) ◽  
pp. 2923-2927 ◽  
Author(s):  
André L. Beauchamp ◽  
Bernard Saperas ◽  
Roland Rivest

The compound cis-Hg(SCN)2(Phen)2 belongs to the triclinic space group [Formula: see text] with a = 13.252(5), b = 11.077(4), c = 8.443(3) Å, α = 105.20(3), β = 83.25 (3), γ = 90.92(3)°, and Z = 2. The structure was solved by the heavy atom method and refined on 1718 independent reflections to an R factor of 0.069. The crystal contains discrete molecules, in which mercury is coordinated to four nitrogen atoms from two phenanthroline molecules and to two sulfur atoms from thiocyanate groups. These donor atoms define a distorted octahedral geometry around mercury. The Hg—N bond lengths are in the range 2.42(2)–2.52(2) Å, whereas the Hg—S bonds are equal to 2.622(8) and 2.582(8) Å. The molecules are packed in layers parallel to the (110) planes and the layers are held together by normal van der Waals interactions. Within the layers, the packing of the complex is characterized by parallel stacking of phenanthroline ligands at distances of ∼3.4 Å. The terminal nitrogen atoms of the thiocyanate groups are uncoordinated.


Author(s):  
Hans Reuter ◽  
Martin Reichelt

The title compound, (2,2′-bipyridine-κ2N,N′)triiodidomethyltin(IV), [Sn(CH3)I3(C10H8N2)], crystallizing in the non-centrosymmetric orthorhombic space groupPca21as an inversion twin, represents one of the few structurally characterized coordination compounds of an organotin(IV) trihalide with 2,2′-biypridine. Its distorted octahedral geometry shows a meridional arrangement of the I atoms and the methyl group is in-plane with the five-membered chelate ring. Asymmetric bonding of the biypridine ligand to the tin(IV) atom is reflected by different Sn—N bond lengths [2.268 (4) Åversus2.293 (4) Å] and caused by the statictranseffect of the methyl group. Sn—I bond lengths show some differences with respect to their orientation to the methyl group or the bipyridine ligand, respectively. Angular distortions in the coordination sphere of the SnIVatom mainly arise from the large I atoms. Distortion of the 2,2′-bipyridine ligand as a result of its coordination to the SnIVatom are described by the twisting angle of 2.5 (2)° between the least-squares planes of the two pyridine rings, as well as by the angle of 6.2 (2)° between the two lines through the pyridine-connecting C atoms and thepara-orientated C atoms. Directional intermolecular interactions are restricted to weak I...H van der Waals contacts.


1999 ◽  
Vol 77 (12) ◽  
pp. 2033-2038 ◽  
Author(s):  
Ika A Setyawati ◽  
Steven J Rettig ◽  
Chris Orvig

Iron(III) complexation with potentially hexadentate H2bbpen (N,N'-bis(2-hydroxybenzyl)-N,N'-bis(2-methylpyridyl)ethylenediamine) was studied. The resulting monocationic complex, [Fe(bbpen)]+ as its NO3- and PF6- salts, was characterized by infrared spectroscopy, mass spectrometry, elemental analyses, cyclic voltammetry, and X-ray crystallographic analysis. Crystals of [Fe(bbpen)]NO3·CH3OH are monoclinic, space group P21/c, a = 10.2640(13), b = 14.7526(10), c = 18.3172(5) Å, β = 97.904(1)°, and Z = 4. The structure was solved by heavy-atom Patterson methods and refined to an R factor of 0.039 for 3526 reflections with I > 3σ(I). The structure of the [Fe(bbpen)]+ cation showed that the ligand is bound in a hexadentate fashion to the central Fe(III) ion, resulting in a distorted octahedral geometry. Magnetic susceptibility measurements indicated the presence of a high-spin Fe(III) ion, and the UV-vis spectrum of [Fe(bbpen)]NO3 exhibits absorption maxima, λmax, at 575 nm (ε = 5400 M-1 cm-1), 323 (8900), and 275 (13 500). The cyclic voltammogram of [Fe(bbpen)]NO3 showed a quasi-reversible, one-electron process corresponding to [FeIII(bbpen)]+ + e- <_> [FeII(bbpen)] at -0.47 V vs. SCE.Key words: cationic, iron(III), phenolate, pyridyl, hexadentate.


2012 ◽  
Vol 68 (6) ◽  
pp. m824-m825 ◽  
Author(s):  
Ichraf Chérif ◽  
Jawher Abdelhak ◽  
Mohamed Faouzi Zid ◽  
Ahmed Driss

In the crystal structure of the title compound, (C5H6ClN2)[Cr(C2O4)2(H2O)2]·1.5H2O, the CrIII atom adopts a distorted octahedral geometry being coordinated by two O atoms of two cis water molecules and four O atoms from two chelating oxalate dianions. The cis-diaquadioxalatochromate(III) anions, 2-amino-5-chloropyridinium cations and uncoordinated water molecules are linked into a three-dimensional supramolecular array by O—H...O and N—H...O hydrogen-bonding interactions. One of the two independent lattice water molecules is situated on a twofold rotation axis.


2003 ◽  
Vol 58 (9) ◽  
pp. 916-921 ◽  
Author(s):  
Amitabha Datta ◽  
Samiran Mitra ◽  
Georgina Rosair

Two new bimetallic complexes [Zn(phen)3][Fe(CN)5(NO)] · 2 H2O · 0.25 MeOH, (1) and [(bipy)2(H2O)Zn(μ-NC)Fe(CN)4(NO)] · 0.5 H2O, (2), have been isolated (where phen = 1,10-phenanthroline and bipy = bipyridyl) and characterised by X-ray crystallography [as the 2 H2O · 0.25 CH3OH solvate for (1) and hemihydrate for (2)] infrared spectroscopy and thermogravimetric analysis. Substitution of phenanthroline for bipyridyl resulted in a cyano-bridged bimetallic species rather than two discrete mononuclear metal complexes. The bond angles of Fe-N-O were shown to be practically linear for both 1 [179.2(7)°] and 2 [178.3(3)°], and the Zn atoms have distorted octahedral geometry. The solvent molecules in both crystal lattices take part in forming hydrogen-bonded networks.


2012 ◽  
Vol 68 (8) ◽  
pp. m1055-m1055 ◽  
Author(s):  
M. Mobin Shaikh ◽  
Veenu Mishra ◽  
Priti Ram ◽  
Anil Birla

The structure of the centrosymmetric title complex, [Cu(C5H9O2)2(C6H7NO)2], has the CuIIatom on a centre of inversion. The CuIIatom is six-coordinate with a distorted octahedral geometry, defined by the N and O atoms of the chelating 2-(2-hydroxymethyl)pyridine ligands and two carboxylate O atoms from two monodentate pivalate ions. The crystal packing is stabilized by intermolecular C—H...O and intramolecular O—H...O hydrogen-bond interactions.


2009 ◽  
Vol 65 (6) ◽  
pp. m702-m702 ◽  
Author(s):  
Wen-Dong Song ◽  
Hao Wang ◽  
Shi-Jie Li ◽  
Pei-Wen Qin ◽  
Shi-Wei Hu

In the title mononuclear complex, [Co(C9H4N2O4)(H2O)5]·5H2O, the CoIIatom exhibits a distorted octahedral geometry involving an N atom of a 1H-benzimidazole-5,6-dicarboxylate ligand and five water O atoms. A supramolecular network is generated through intermolecular O—H...O hydrogen-bonding interactions involving the coordinated and uncoordinated water molecules and the carboxyl O atoms of the organic ligand. An intermolecular N—H...O hydrogen bond is also observed.


2018 ◽  
Vol 34 (4) ◽  
pp. 1937-1944 ◽  
Author(s):  
Vijay Kumar ◽  
Rajiv Kumar Singh ◽  
Veena Kumari ◽  
Birendra Kumar ◽  
Shivadhar Sharma

The ligand, 3-hydroxy-4-methoxybenzaldehydethiosemicarbazone has been prepared by the condensation of 3-hydroxy-4-methoxybenzaldehyde and thiosemicarbazide. With the help of this ligand the complexes of Co(II), Ni(II) and Cu(II) have been prepared with general formula [ML2X2] where X is secondary ligand, Cl–, NO3– and CH3COO–. The composition of complexes has been established by their microanalysis, while the metal contents have been determined gravimetrically and volumetrically. On the basis of IR spectra, the coordinating mode of ligand has been determined and has been found to have coordinated through azomethine nitrogen and thione sulphur. The magnetic moment of Co(II) complexes has been found between 4.96-4.72 B. M. The value is slightly higher than the μs value corresponding to three unpaired electrons (3.872 B.M). The increase in value may be attributed to orbital contribution from 4T1g ground state cubic term. The appearance of four bands in their electronic spectra is indicative of tetragonally distorted octahedral geometry of Co(II) complexes. The magnetic moment (3.20-3.30 B. M.) and appearance of 4 bands in the electronic spectra of Ni(II) complexes confirms the distorted octahedral geometry of the complexes. The magnetic moment of Cu(II) complexes has been determined to be (1.95-2.20 B. M.) which shows that Cu(II) complexes are magnetically dilute complexes. The appearance of three bands in their electronic spectra confirms John - Tellor distortion in octahedral symmetry of Cu(II) complexes. The various crystal field parameters exhibiting tetragonal distortion in the octahedral symmetry have also been derived. The positive value of Dt predicts tetragonal elongation in Oh symmetry.


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