The crystal structures and properties of [VCL3(THF)2(H2O] and [VCl3(THF)2(H2O)]·THF (original) (raw)
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Inorganic Chemistry, 2010
The molecular geometries of VCl 2 and VCl 3 have been determined by computations and gas-phase electron diffraction (ED). The ED study is a reinvestigation of the previously published analysis for VCl 2 . The structure of the vanadium dichloride dimer has also been calculated. According to our joint ED and computational study, the evaporation of a solid sample of VCl 2 resulted in about 66% vanadium trichloride and 34% vanadium dichloride in the vapor. Vanadium dichloride is unambiguously linear in its 4 Σ g þ ground electronic state. For VCl 3 , all computations yielded a Jahn-Tellerdistorted ground-state structure of C 2v symmetry. However, it lies merely less than 3 kJ/mol lower than the 3 E 00 state (D 3h symmetry). Due to the dynamic nature of the Jahn-Teller effect in this case, rigorous distinction cannot be made between the planar models of either D 3h symmetry or C 2v symmetry for the equilibrium structure of VCl 3 . Furthermore, the presence of several low-lying excited electronic states of VCl 3 is expected in the high-temperature vapor. To our knowledge, this is the first experimental and computational study of the VCl 3 molecule.
Electronic states of vanadium(III) in trans-VCl 2(H 2O) 4 + chromophore
Journal of Alloys and Compounds, 2008
The polarized absorption spectra of vanadium(III) in Cs 3 VCl 6 ·4H 2 O complex are presented in the UV-vis region and correspond to the transition from the ground state 3 T 1g ( 3 F) to the excited states 3 T 2g ( 3 F), 3 T 1g ( 3 P) and 3 A 2g ( 3 F). Semiempirical calculations of the crystal-field levels of the vanadium(III) with D 4h point group symmetry in Cs 3 VCl 6 ·4H 2 O chromophore are carried out, leading to a good agreement between the theoretical and experimental energy levels.
Journal of the Chemical Society, Dalton Transactions, 1998
The reaction between [VCl 3 (thf) 3 ] and Cl Ϫ provided a high-yield route to [NEt 4 ] 3 [V 2 Cl 9 ] 1, which contains a [V 2-(µ-Cl) 3 Cl 6 ] 3Ϫ face-sharing bioctahedron. The reaction of [VCl 3 (thf) 3 ] with sodium 2-sulfanylbenzoate (mba 2Ϫ) in the presence of water and PPh 4 Cl gave [PPh 4 ] 2 [V 3 OCl 4 (Hmba) 5 ] 2, whose anion contains a triangular [V 3 (µ 3-O)] 7ϩ core. The reaction of [NEt 4 ] 2 [VOCl 4 ] with H 2 mba and Li 2 S gave [NEt 4 ] 4 [V 2 Li 4 O 2 Cl 4 (mba) 4 ] 3, whose anion contains two [VO(mba)] fragments bridged by a [Li 4 Cl 4 ] unit. Compounds 1 and 2 are weakly antiferromagnetically coupled with J = Ϫ13.4(4) and Ϫ3.2(1.6) cm Ϫ1 , respectively (Ĥ = Ϫ2JS i S j convention). We have been interested for some time in the synthesis and characterisation of vanadium complexes with a variety of nuclearities and ligand types and in the metal oxidation state range -, including mixed valency. 1-4 This interest has encompassed both the preparation of new structural types and a study of their spectroscopic and physical properties. Recently, a study of vanadium carboxylates was initiated and to date we have reported several species, including trinuclear [V 3 O-(O 2 CR) 6 (py) 3 ]ClO 4 (R = Me, Et, Ph, etc.; py = pyridine), 2 tetranuclear [V 4 O 2 (O 2 CEt) 7 (bpy) 2 ]ClO 4 3 (bpy = 2,2Ј-bipyridine) and [NEt 4 ] 2 [V 4 O 8 (NO 3)(O 2 CC 4 H 4 S) 4 ], 4 and pentanuclear [NR 4 ] 2-[V 5 O 9 X(O 2 CPh) 4 ] (X = Cl or Br), 4 together with their NMR, EPR, electrochemical and magnetic properties. In the present paper are described three species of differing nuclearity, two of which have resulted from attempts to incorporate a carboxylate derivative also containing a thiolate group, i.e. 2-sulfanylbenzoic acid (H 2 mba), in the hope that the bifunctional ligand would yield new types of V x products. Also described are a convenient preparation of the known [NEt 4 ] 3 [V 2 Cl 9 ] in a form suitable for crystallography, and the magnetic characterisation of two V III-containing complexes. Experimental General All manipulations were performed under a purified argon atmosphere employing standard Schlenk and glove-box techniques. Acetonitrile, Et 2 O and EtOH were distilled under argon from 4 Å molecular sieves, sodium-benzophenone solution, and ethyl Grignard, respectively. The compound [VCl 3 (thf) 3 ] (thf = tetrahydrofuran) was prepared from VCl 3 (Aldrich) as described in the literature. 5 [NEt 4 ] 2 [VOCl 4 ] from VOSO 4 ؒnH 2 O, LiCl, and NEt 4 Cl, 4 Na 2 [SC 6 H 4 CO 2 ] (Na 2 mba) was prepared from sodium ethoxide and 2-sulfanylbenzoic acid (H 2 mba, Aldrich) in EtOH. The 2-sulfanylbenzoic acid was used as received. Preparations [NEt 4 ] 3 [V 2 Cl 9 ] 1. The compounds [VCl 3 (thf) 3 ] (0.74 g, 2.0 mmol) and NBu n 4 Cl (0.83 g, 3.0 mmol) were dissolved in † Non-SI unit employed: µ B ≈ 9.27 × 10 Ϫ24 J T Ϫ1. CH 2 Cl 2 (20 cm 3) to give a purple solution. This was layered carefully with a solution of NEt 4 Cl (0.50 g, 3.0 mmol) in CH 2 Cl 2 (20 cm 3). Purple crystals of 1ؒ5CH 2 Cl 2 slowly formed as the two solutions mixed, and they were collected by filtration, washed with hexanes and dried in vacuo. The yield was 85%.
Inorganic Chemistry, 2004
Spectroscopic and crystallographic data are presented for salts containing the [V(OH 2 ) 6 ] 3+ cation, providing a rigorous test of the ability of the angular overlap model (AOM) to inter-relate the electronic and molecular structure of integer-spin complexes. High-field multifrequency EPR provides a very precise definition of the ground-state spin-Hamiltonian parameters, while single-crystal absorption measurements enable the energies of excited ligand-field states to be identified. The EPR study of vanadium(III) as an impurity in guanidinium gallium sulfate is particularly instructive, with fine-structure observed attributable to crystallographically distinct [V(OH 2 ) 6 ] 3+ cations, hyperfine coupling, and ferroelectric domains. The electronic structure of the complex depends strongly on the mode of coordination of the water molecules to the vanadium(III) cation, as revealed by single-crystal neutron and X-ray diffraction measurements, and is also sensitive to the isotopic abundance. It is shown that the AOM gives a very good account of the change in the electronic structure, as a function of geometric coordinates of the [V(OH 2 ) 6 ] 3+ cation. However, the ligand-field analysis is inconsistent with the profiles of electronic transitions between ligandfield terms.
Influence of the Mode of Water Coordination on the Electronic Structure of the [V(OH 2) 6] 3+ Cation
Journal of Solid State Chemistry, 1999
The correlation between the stereochemistry and electronic structure of the [V(OH 2 ) 6 ] 3؉ cation has been examined using a variety of physical techniques in conjunction with angular overlap model calculations. The experimental data includes the 5rst reported high-5eld, high-frequency EPR study of a vanadium(III) complex which enables a precise determination of the ground term spin-Hamiltonian parameters. The electronic structure and vibrational spectrum of the [V(OH 2 ) 6 ] 3؉ cation was studied in samples formed from the co-crystallization of RbV(SO 4 ) 2 ' 12H 2 O and RbGa(SO 4 ) 2 ' 12H 2 O. The structural modi5cations of these salts di4er in terms of the orientation of the water molecules about the tervalent cation while the M III O 6 framework remains approximately octahedral. The electronic structure of the [V(OH 2 ) 6 ] 3؉ cation in samples of Rb[Ga:V] (SO 4 ) 2 ' 12H 2 O is found to depend greatly on the relative proportions of gallium(III) and vanadium(III). The experimental data are in accordance with predictions based on the angular overlap model when the -bonding normal to the plane of the water molecule is dominant over the in-plane interaction (e N !e # ca. 930 cm !1 for trigonal planar water coordination). The -anisotropy results in a large trigonal 5eld splitting of the 3 T 1g (O h ) ground term in RbV(SO 4 ) 2 ' 12H 2 O (1930 cm !1 ) which diminishes almost to zero when [V(OH 2 ) 6 ] 3؉ is doped into RbGa(SO 4 ) 2 ' 12H 2 O, on account of the change in the orientation of the water molecules imposed by hydrogen bonding constraints. This work demonstrates the strong correlation between the stereochemistry and electronic structure of the [V(OH 2 ) 6 ] 3؉ cation and accounts for the structural abnormalities reported for vanadium(III) salts of this type.
Inorganic Chemistry, 1987
The synthesis, structure, and properties of V20(Me2-aet)4 (Me-aet is 2-(dimethylamino)ethanethiolate) are reported. The synthesis and properties of corresponding V20(aet)4 (aet is 2-aminoethanethiolate) are also described. V20(Me2-aet)4.toluene.THF crystallizes in triclinic space group PI with the following unit cell dimensions (at --154 "C): a = 12.156 , b = 14.379 (4), c = 11.521 (3) A; a = 113.57 (I), 0 = 104.70 (2), y = 66.07 (1)O; 2 = 2. The molecule possesses an essentially linear V-0-V bridging unit (177.84 (25)O). Each V is in approximate trigonal-bipyramidal coordination geometry with the bridging 0 and two thiolate S atoms occupying equatorial positions and two N atoms in the axial positions. The N-V-N axes at the two ends of the molecule are staggered (torsional angles 89.26-90.57') to yield a molecule with idealized S4 symmetry. The electronic makeup
Inorganic Chemistry, 1990
Reaction of [V2(p-CI)3(THF)6]2[zn2c16] with a slight excess of the nitrogen-containing ligand L [L = amine, pyridine] ruptured the bimetallic structure, allowing the large-scale preparation of the mononuclear high-spin V(I1) derivatives trans-L4VC12 [L = N,N,N'-trimethylethylenediamine (Z), pyrrolidine (3), pyridine (4)] in crystalline form and good yield. Crystal data for 1 are as follows: monoclinic, P2,/n, a = 7.900 (3) A, b = 12.345 (5) A, c = 9.142 (3) A, fl = 97.33 (3)O, V = 884.3 (7) A3, Z = 2. These complexes are versatile starting materials for the preparation of various V(I1) complexes including the first dinitrogen derivative [ ( p y ) ( M~)~V l~( p N~) (5) [Mz = O -C~H~C H~N ( C H~)~] and the monomeric aryl tram-Mz,V(py), (6). Crystal data for 6 are as follows: monoclinic, P2,/c, a = 9.990 (1) A, b = 15.536 ( 1 ) A, c = 16.369 (1) A, fl = 95.17 (l)', V = 2530.2 TMEDA (l), (3) A', z = 4. ' Rijksuniversiteit Groningen. *University of Ottawa. 5 Rijksuniversiteit Utrecht. retarding factor in the development of this chemistry has been the lack of suitable V(I1) starting materials. In fact, although (1) (a) Denisov, N. T.; Efimov, 0. N.; Shuvalova, N. 1.; Shilova, A. K.; Shilov, A. E. Zh. Fiz. Khim. 1970, 44, 2694. (b) Shilov, A. E.; Denisov, N. T.; Efimov, 0. N.; Shuvalov, N. F.; Shuvalova. N. I.; Shilova, E. Nature (London) 1971, 231, 460. (c) Zones, S . I.; Vickrey, T. M.; Palmer, J. G.; Schrauzer, G. N. J. Am. Chem. Soc. 1976,98,7289. (d) Zones, S. 1.; Palmer, M. R.; Palmer, J. G.; Doemeny, J. M.; Schrauzer, G.
Journal of Chemical Crystallography, 2000
The title complex was prepared from the reaction of [V 2 (µ-Cl) 3 (thf) 3 ] 2 [Zn 2 Cl 6 ] with N ,N ,N N-tetraethylethane-1,2-diamine (teeda) in refluxing thf and its crystal structure exhibits two triangulo-[V 3 (µ-Cl) 3 (µ 3-Cl)(µ 3-OH)(thf) 2 (teeda)] + cations bridged by two chlorides. The molecular structure (monoclinic, space group P2 1 /n, Z = 2, a = 11.8005(7)Å, b = 18.7492(14)Å, c = 15.6253(9)Å, β = 103.600(4) shows each vanadium site in a distorted octahedral geometry. V1 and V2 have two thf molecules bounded in cis configuration, and V3 completes the hexa-coordination with the diamine teeda. Main bond distances are 2.5149(12)Å for V(1)-µ-Cl(1), 2.062(3)Å for V(1)-µ 3-O(3), 2.5554(12)Å for V(1)-µ 3-Cl(4), 2.140(3)Å for V(1) O(1)(thf), 2.243(4)Å for V(3) N(1)(teeda), and 3.0437(9) for V(1)• • •V(2).
Inorganic Chemistry, 1993
A high-yield synthetic route (90% isolated yield) has been found for the first paddle-wheel divanadium compound with a u27r4 triple bond, V2(DFM)4 (DFM-= [ (p-tolyl)NCHN(p-tolyl)]-). The molecule has been characterized by IH NMR, which shows that it is diamagnetic, with a very largediamagnetic anisotropy, and by X-ray crystallography. It is dimorphous, but the molecules are essentially the same in both forms. In the tetragonal form (space group P4/n,a= 13.214(6)A,c= 17.427(5)A,Z=2, V = 3043(3)A3)V-V = 1.978(2)Aandthetorsionangleis5.4(2)'. In the orthorhombic form (space group Pccn, a = 15.555(2) A, b = 16.914(4) A, c = 24.768(1) A, Z = 4, V = 6516(2) A3) V-V = 1.975(4) A and the mean torsion angle is 9.6(6)'. The key step in the synthesis is the use of a THF solution of VCl3(THF)3 which has been reduced by 1 equiv of NaHBEt3. The compound V(DFM)3 has also been prepared and characterized. It is a tris-chelate compound, strongly distorted from octahedral coordination due to the small bite of the DFM ligands. It forms crystals in space group C 2 / c with a = 12.693(4) A, b = 33.109(6) A, c = 9.21 l(3) A, Z = 4, and V = 3863(2) A3.