Gehinderte Ligandbewegungen in Übergangsmetallkomplexen, XXXVII [1]: Photoreaktion von Dekacarbonyldirhenium mit Phenylallen / Hindered Ligand Motions in Transition Metal Complexes, XXXVII [1]: Photoreaction of Decacarbonyldirhenium with Phenylallene

1990 ◽  
Vol 45 (6) ◽  
pp. 793-802 ◽  
Author(s):  
Cornelius G. Kreiter ◽  
Wolfgang Michels ◽  
Reiner Exner
Keyword(s):  
Molecular Structure ◽  
Solid State ◽  
Transition Metal ◽  
Transition Metal Complexes ◽  
Crystal And Molecular Structure ◽  
Dinuclear Complexes ◽  
Rotation Barrier ◽  
Single Bond ◽  
Hindered Rotation ◽  
X Ray

Decacarbonyldirhenium (1) and phenylallene (2) form upon UV irradiation four dinuclear complexes: Decacarbonyl-μ-η1:1-(3,4-diphenyl-1,5-hexadien-2,5-diyl)-dirhenium (3), enneacarbonyl-μ-ηl:3-(3-phenyl-2-propen-1,2-diyl)-dirhenium (4), octacarbonyl-μ-hydrido-μ-η1:2-(3-phenyl-1,2-propadien-l-yl)-dirhenium (5) and octacarbonyl-μ-η2:2-(phenyl-1,2-propadiene)-dirhenium (6). The thermolabile complex 4 looses CO and forms the phenylallene bridged compound 6. Similarly 5 is rearranged to 6 by transfer of the hydrido ligand to the 3-phenyl-1,2-propadien-1-yl bridge. The formation of 3 and 4 can be rationalized via pentacarbonyl-phenylpropenediyl-rhenium radicals which dimerize to give 3 or add pentacarbonylrhenium radicals, loose CO and form 4. The crystal and molecular structure of 3 was determined by X-ray structure analysis. In the solid state the molecule is present in the ± ap conformation. In solution at 233 K the ±ap, +sc, and –sc conformations are equally populated. By a hindered rotation around a CC single bond, the three conformers are interconverted with a rotation barrier of ΔG*258 = 52.3 ± 1 kJ · mol-1.

scholarly journals Transition metal complexes with thiosemicarbazide-based ligand: Part 45 - Synthesis, crystal and molecular structure of [2, 6-diacetylpyridine bis(S-methylisothiosemicarbazonato)]diazide-iron(III)

2003 ◽  
Vol 68 (4-5) ◽  
pp. 425-433 ◽  
Author(s):  
Vukadin Leovac ◽  
Vladimir Divjakovic ◽  
Valerija Cesljevic ◽  
Refik Fazlic
Keyword(s):  
Molecular Structure ◽  
Transition Metal ◽  
Transition Metal Complexes ◽  
Equatorial Plane ◽  
Crystal And Molecular Structure ◽  
Crystal Data ◽  
X Ray ◽  
High Spin Complex ◽  
Spin Complex ◽  
Template Reaction

The template reaction of a warm methanolic solution of FeCl3.6H2O S-methylisothiosemicarbazidehydroiodide and 2,6-diacetylpyridine in the presence of LiOAc and NaN3 yielded the high-spin complex [Fe(HL)(N3)2], were HL is the monoanion of the ligand 2,6-diacetylpyridine bis(S-methylisothiosemicarbazone). X-Ray analysis of the complex showed its pentagonal-bipyramidal configuration, with pentadenate (N5) HL in the equatorial plane and two monodentate azide groups in the axial positions. Crystal data are: monoclinic, P21/c,a=1.0263(2), b = 1.2525(2), c = 1.6660(3) nm, ?= 98.94?, V = 2.1154 nm3, Z = 4, ?x = 1.499 g cm-3, ?0 = 1.48 g cm-3, F(000) = 984, ?= 9.40 cm-1.

Gehinderte Ligandbewegungen in Übergangsmetallkomplexen, XLII [1]: Photoreaktionen von Hexacarbonyl-μ-η5:5-fulvalen-dimolybdän und -diwolfram mit konjugierten Dienen / Hindered Ligand Movements in Transition Metal Complexes, XLII [1]: Photoreactions of Hexacarbonyl-μ–η5:5-fulvalene-dimolybdenum and -ditungsten with Conjugated Dienes

1993 ◽  
Vol 48 (11) ◽  
pp. 1635-1650 ◽  
Author(s):  
Cornelius G. Kreiter ◽  
Wolfgang Conrad ◽  
Reiner Exner
Keyword(s):  
Molecular Structure ◽  
Transition Metal ◽  
Diffraction Analysis ◽  
Transition Metal Complexes ◽  
Energy Barrier ◽  
Crystal And Molecular Structure ◽  
Conjugated Dienes ◽  
Photochemical Reactions ◽  
X Ray Diffraction ◽  
X Ray

Photochemical reactions of hexacarbonyl-μ-η5:5-fulvalene-dimolybdenum (1) with 1,3-butadiene (a), 2-methyl-1,3-butadiene (b), E-1,3-pentadiene (c), 2,3-dimethyl-1,3-butadiene (d), and E-3-methyl-1,3-pentadiene (e) yield the corresponding tetracarbonyl-η4-s-cisdiene-μ-η5:5-fulvalene-dimolybdenum complexes 3a-3e. In addition to 3a also η4-s-trans1,3-butadiene-tetracarbonyl-μ-η5:5-fulvalene-dimolybdenum (4) is formed. Similarily hexacarbonyl-μ-η5:5-fulvalene-ditungsten (2) forms with a and b tetracarbonyl-η4-s-cis-diene-μ-η5:5-fulvalene-ditungsten (5a, 5b) and bis(η4-s-cis-1,3-butadiene)-dicarbonyl-μ-η5:5-fulvalene-ditungsten (6). The complexes 3b —3e and also 5b are obtained as mixtures of the o- and u-isomers. Only for tetracarbonyl-η4-cis-2,3-dimethyl-1,3-butadiene-μ-η5:5-fulvalene-dimolybdenum (3d) an interconversion of the o- and u-isomers is observed with an energy barrier of ΔG183# = 73.9 kJ/mol. Both isomers of 3d show hindered inversions with energy barriers of ΔG#313 = 66.1 kJ/mol (u-3d) and ΔG183# = 36.4 kJ/mol (o-3d). For o-3d the crystal and molecular structure was determined by an X-ray diffraction analysis. Hexacarbonylµ — η5:5-bis(cyclopentadiendiyl)methane-dimolybdenum (7), hexacarbonyl-μ-η5:5-bis(cyclopentadiendiyl)ethane-dimolybdenum and hexacarbonyl-μ-η5:5-bis(cyclopentadiendiyl)propane-dimolybdenum do not react with conjugated dienes. Upon UV irradiation 7 looses CO and forms by dimerization octacarbonyl-bis(μ-η5:5-(cyclopentadiendiyl-cyclopentadien-triyl)methane)-dihydrido-tetramolybdenum (8).

Heavy transition metal complexes of biologically important molecules. I. The crystal and molecular structure of trans-dichloro(bis(isopropyl)-sulfoxide-S)(1-methylcytosine-N)platinum(II)

1976 ◽  
Vol 54 (1) ◽  
pp. 53-58 ◽  
Author(s):  
Colin James Lyne Lock ◽  
Robert Anthony Speranzini ◽  
John Powell
Keyword(s):  
Molecular Structure ◽  
Transition Metal ◽  
Metal Complexes ◽  
Single Crystal ◽  
Least Squares ◽  
Transition Metal Complexes ◽  
Crystal And Molecular Structure ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray

The crystal and molecular structure of trans-dichloro(bis(isopropyl)sulfoxide-S)(1-methylcytosine-N)platinum(II) has been determined by single crystal X-ray diffraction. The crystals are triclinic with a = 16.205(5), b = 8.078(2), c = 6.776(2) Å, α = 106.53(2), β = 96.35(2), γ = 98.54(2)°. The space group is [Formula: see text] and there are two molecules per unit cell. A total of 2294 independent reflections, of which 2023 were observed, were examined on a Syntex [Formula: see text] diffractometer. The structure was refined by full matrix least squares analysis to an R2 value of 0.0427. The ligands form a rough square around the platinum atom with Pt—Cl(1), 2.304(3), Pt—Cl(2), 2.287(4), Pt—S, 2.232(2), Pt—N, 2.058(7). Distances within the ligands are normal. The plane of the cytosine ring is at 84.4° to the plane formed by the ligands around platinum.

Transition Metal Complexes of Diazenes, XVII [1]. Reactions of 1,2-Diazetines and 1,2-Diazetine-N-oxides with Iron Carbonyls

1982 ◽  
Vol 37 (4) ◽  
pp. 463-467 ◽  
Author(s):  
A. Albini ◽  
H. Kisch ◽  
C. Krüger ◽  
An-Pei Chiang
Keyword(s):  
Molecular Structure ◽  
Transition Metal ◽  
Metal Complexes ◽  
Electronic Properties ◽  
Transition Metal Complexes ◽  
Lone Pair ◽  
X Ray ◽  
Iron Carbonyls

Enneacarbonyldiiron reacts with 3,3,4,4-tetramethyl-1,2-diazetine (L) or its mono-N-oxide (L′) to form complexes (L)Fe(CO)4 (3), (L)Fe2(CO)7 (4), (L)Fe2(CO)6 (5), or (L′)Fe(CO)4 (6), and small amounts of deoxygenated 4 and 5, respectively. Formation and stability of the complexes is compared with those of ligands with smaller and larger ring sizes and discussed in terms of the electronic properties of the ligand lone-pair Orbitals. The molecular structure of 4 is established by X-ray analysis.

The crystal and molecular structure of 1,4-diphenyl-2,2′,3,3′,5,5′,6,6′-octamethylcyclo-1,4-diphospha-2,3,5,6-tetrasilahexane, a phosphorus–silicon heterocycle

1979 ◽  
Vol 57 (2) ◽  
pp. 174-179 ◽  
Author(s):  
A. Wallace Cordes ◽  
Paul F. Schubert ◽  
Richard T. Oakley
Keyword(s):  
Molecular Structure ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Chair Conformation ◽  
Monoclinic Space Group ◽  
Single Bond ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray ◽  
Bond Lengths

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.

Interaction of diiodine with some tetra-substituted dithiooxamides. Crystal and molecular structure of bis(morpholinothiocarbonyl)bis(diiodine)

1988 ◽  
Vol 66 (6) ◽  
pp. 1483-1489 ◽  
Author(s):  
Davide Atzei ◽  
Paola Deplano ◽  
Emanuele F. Trogu ◽  
Francesco Bigoli ◽  
Maria Angela Pellinghelli ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Charge Transfer ◽  
Solid State ◽  
Torsion Angle ◽  
Crystal And Molecular Structure ◽  
Formation Constants ◽  
Dalton Trans ◽  
X Ray ◽  
Space Groups ◽  
Spectrophotometric Methods

The reaction of some tetra-substituted dithiooxamides R2NC(S)C(S)NR2 (R = CH3:Me4dto; R = C2H5:Et4dto; R2N = OC4H8N:Mo2dto) with diiodine has been investigated by spectrophotometric methods in CHCl3. The formation in solution of 1:1 and 1:2 charge-transfer (c.t.) complexes between the reagents has been observed. A new computer program, derived from "SUPERQUAD" (P. Gans, A. Sabatini, and A. Vacca. J. Chem. Soc. Dalton Trans. 1195 (1985)), has been applied to evaluate the formation constants. The 1:2 c.t. complexes have been isolated in the solid state, and an X-ray structure analysis of the [OC4H8NC(S)C(S)NC4H8O]•2I2 compound indicated that the crystals are triclinic, space groups [Formula: see text], with a = 14.659(6), b = 15.111(6), c = 9.317(5) Å, α = 92.29(2), β = 99.71(2), γ = 99.48(2)° and Z = 4. In particular the torsion angle S—C—C—S (≈90°) shows that the conformation of the dithiooxamide is not trans.

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