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1.
Free P(SMe)3 molecule was studied by gas electron diffraction (GED) and by B3PW91/6-311+G* (DFT) and MP2/6-31+G* calculations. Each conformer is characterized by three dihedral angles τ(CSPlp), where lp denotes the direction of the lone electron lone pair on the P atom. DFT calculations indicate that the most stable conformer is an anti,gauche+,gauche- (ag+g-) conformer of C s symmetry; the next are the ag+g+ (ΔE = 2.5 kJ mol−1), g+g+g+ (ΔE = 5.2 kJ mol−1), and aa+g+ (Δ E = 12.5 kJ mol−1) conformers. The MP2 calculations give the similar order, with the relative energies of 0.3, 4.3, and 10.6 kJ mol−1, respectively. The experimental GED data agree well with the presence of only two conformers: χ(ag+g+) = 80(20)% and χ(ag+g-) = 20(10)%.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 5, 2005, pp. 742–750.Original Russian Text Copyright © 2005 by Belyakov, Khramov, Baskakova, Naumov.  相似文献   

2.
The molecular structure of axial and equatorial conformer of the 1-chloro-1-silacyclohexane molecule, CH2(CH2CH2)2SiH-Cl, as well as thermodynamic equilibrium between these species were investigated by means of gas-phase electron diffraction and quantum chemistry on the MP2(full)/AUG-cc-PVTZ level of theory. According to electron diffraction data, the compound exists in the gas-phase as a mixture of conformers possessing the chair conformation of the six-membered ring and Cs symmetry and differing in the axial and equatorial position of the Si-Cl bond at 352 K. NBO analysis revealed that axial conformer of 1-chloro-1-silacyclohexane molecule is an example of the stabilization of the form that is unfavorable from the point of view steric effects and effects of conjugations and that stabilization is achieved due to electrostatic interactions.  相似文献   

3.
The reaction of [Cp*2RuBr]+Br− with bromine in CH2Cl2 (CD2Cl2) in an inert atmosphere at room temperature produces the complexes [Cp*Ru(Br)C5Me4CH2Br]+Br3 − (syn conformer), [Cp*Ru(Br)C5Me3(CH2Br)2]+ (syn and anti conformers), and [Ru(Br)(C5Me4CH2Br)2]+ (syn conformer). All complexes were characterized by 1H and 13C NMR spectroscopy; the former complex, by elemental analysis. These complexes were also prepared by the reaction of [Cp*RuC5Me4CH2]+BF4 − with bromine in CH2Cl2. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2712–2718, December, 2005.  相似文献   

4.
The synthesis, characterization and thermal analysis of the novel cyclometallated compounds [Pd2(dmba)2Cl2(μ-bpe)] (1), [Pd2(dmba)2(N3)2(μ-bpe)] (2), [Pd2(dmba)2(NCO)2(μ-bpe)] (3), [Pd2(dmba)2(SCN)2(μ-bpe)] (4), [Pd2(dmba)2(NO3)2(μ-bpe)] (5) (bpe=trans-1,2-bis(4-pyridyl)ethylene; dmba=N,N-dimethylbenzylamine) are described. The thermal stability of [Pd2(dmba)2X2(μ-bpe)] complexes varies in the sequence 1>4>3>2>5. The final residues of the thermal decompositions were characterized as metallic palladium by X-ray powder diffraction.  相似文献   

5.
Complexation between crystalline trans-[Pd(H2O)2(NO3)2] and acetylacetone was studied. The complexes Pd2(Acac)2(μ-NO3)2(I) and Pd2(Acac)2(μ-Acac)(μ-NO3)(II) were obtained and examined by elemental analysis, X-ray powder diffraction analysis, differential scanning calorimetry, simultaneous thermal analysis, mass spectrometry, and vibrational spectroscopy.  相似文献   

6.
Methods were developed for the controlled thermal synthesis of high-spin cubane-like pivalates {MII 4(μ3−OR)4} (M = Co or Ni; R = H or Me) starting from mono-and polynuclear complexes. The solid-state thermal decomposition of the known pivalate clusters [MII 4(μ3−OMe)4−(μ2−OOCBut)2(η2−OOCBut)2(MeOH)4] and the new clusters [M4II(μ3)−OH4(η1−OOCBut)3−(μ−(NH2)2C6H2Me2)3(η1−(NH2)2C6H2Me2)3]+(OOCBut)− (M = Co or Ni) was studied by differential scanning calorimetry and thermogravimetry. The thermolysis of cubane-like CoII and NiII pivalates is a destructive process. The phase composition of the decomposition products is determined by the nature of coordinated ligands and the structural features of the metal core.  相似文献   

7.
The nature of the intermolecular hydrogen bond for the furan-HCl and furan-CHCI3 complexes has been studied using ab initio calculations with MP2 level of theory. The new hydrogen bond type of C(CI)-H...O and π interactions are studied also. It is shown that, for the optimized geometries of furan-CHCI3, C-H bond lengths contract and vibrational frequencies are blue-shifted, while for the furan-HCl complex, H-CI bond lengths elongate and vibrational frequencies are red-shifted. In addition, the NBO analysis indicates that, for the furan-CHCI3 complex, the charge transfers from the lone pair of the proton acceptor to both σ *(CH) antibonding MO and lone pairs of CI atom.  相似文献   

8.
The reactions of the [Mo3(μ3-Q)(μ2-Q)3(H2O)3(C2O4)3]2− complex (Q = S or Se) with CuX salts (X = Cl, Br, I, or SCN) in water produce the cuboidal heterometallic clusters [Mo3(CuX)(μ3-Q)4(H2O)3(C2O4)3]2−, which were isolated as the potassium and tetraphenylphosphonium salts. Two new compounds, K2[Mo3(CuI)(μ3-S)4(H2O)3(C2O4)3]·6H2O and (PPh4)2[Mo3(CuBr)(μ3-S)4(H2O)3(C2O4)3]·7H2O, were structurally characterized. All compounds were characterized by elemental analysis and IR spectroscopy. The K2[Mo3(CuI)(μ3-Se)4(H2O)3(C2O4)3] compound was characterized by the 77Se NMR spectrum; the (PPh4)2[Mo3(CuI)(μ3-S)4(H2O)3(C2O4)3], (PPh4)2[Mo3(CuI)(μ3-Se)4(H2O)3(C2O4)3] and K2[Mo3(CuSCN)(μ3-S)4(H2O)3(C2O4)3]·7H2O compounds, by electrospray mass spectra. Dedicated to Academician G. A. Abakumov on the occasion of his 70th birthday. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1639–1644, September, 2007.  相似文献   

9.
In the compound [Ni(Bptc)2(Bimb)2(H2O)2] (I), where H4Bptc is 3,3′,4,4′-biphenyltetracarboxylic acid; Bimb is 4,4′-bis(1-imidazolyl)biphenyl), Ni(II) has a distorted octahedral coordination geometry, which was bonded with two N atoms from two Bimb ligands, two O atoms from two H2Bptc2− ligands and two water O atoms. The crystal structure of compound I is stabilized by the π-π-stacking and hydrogen bonds interaction.  相似文献   

10.
The reaction of a sulfur and oxygen-bridged 8-quinolinolato trinuclear molybdenum cluster [Mo3OS3(qn)3(H2O)3]+ (3; Hqn = 8-quinolinol) with equimolar amounts of acetylene carboxylic acid, 4-pentynoic acid, 5-hexynoic acid, acetic acid, and pimelic acid gave clusters having μ-carboxylato groups, [Mo3OS3(qn)3(H2O)(μ-HC≡CCOO)] (6), [Mo3OS3(qn)3(H2O)(μ-HC≡C(CH2)2COO)] (7), [Mo3OS3(qn)3(H2O)(μ-HC≡C(CH2)3COO)] (8), [Mo3OS3(qn)3(H2O)(μ-CH3COO)] (4), and [{Mo3OS3(qn)3(C2H5OH)}2(μ-C7H10O4)] (5), respectively. X-ray structural analyses, 1H NMR, and electronic spectra of these clusters made clear that each of the COO− groups of the reagents bridges two Mo atoms in each cluster and that no adduct formation occurred at the sulfurs in the clusters. The reaction of 3 with a large excess-molar amount (50 times) of acetylene carboxylic acid gave [Mo3OS(μ3-SCH=C(COOH)S)(qn)3(H2O)(μ-HC≡CCOO)] (9) with two molecules of acetylene carboxylic acid, one acting as a carboxylato bridge and the other in adduct formation, as supported by the electronic and 1H NMR spectra. The corresponding aqua cluster [Mo3OS3(H2O)9]4+ (1), on the contrary, reacts with acetylene carboxylic acid to give adduct [Mo3OS(μ3-SCH=C(COOH)S)(H2O)9]4+ (2). Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

11.
Energy differences, ΔX s−t (X = E, H, and G) (ΔX s−t = X(singlet) − X(triplet)) between singlet (s) and triplet (t) states of C12H8M were calculated at B3LYP/6-311+G*. The DFT calculations indicated that the ΔG s−t between singlet (s) and triplet (t) states of C12H8M were increased from M = C to M = Pb. The ΔG s−t of C12H8M was compared with its analogue C4H4M through replacement of heavy atoms from M = C to M = Pb. Configurations of the electrons in orbitals (σ2 or π2) for the singlet state of C12H8M were discussed.  相似文献   

12.
The two complexes, [RE(Gly)4(Im)(H2O)](ClO4)3(s)(RE = Eu, Sm), have been synthesized and characterized. The standard molar enthalpies of reaction for the following reactions, RECl3·6H2O(s)+4Gly(s)+Im(s)+3NaClO4(s) = =[RE(Gly)4(Im)(H2O)](ClO4)3(s)+3NaCl(s)+5H2O(l), were determined by solution-reaction colorimetry. The standard molar enthalpies of formation of the two complexes at T = 298.15 K were derived as Δf H mΘ {Eu(Gly)4(Im)(H2O)}(ClO4)3(s)} = = −(3396.6±2.3) kJ mol−1 and Δf H mΘ {Sm(Gly)4(Im)(H2O)}(ClO4)3(s)} = −(3472.7±2.3) kJ mol−1, respectively.  相似文献   

13.
The new alkoxysilyl-functionalized alkynes [HC≡CCH2N(H)C(=O)N(H)(CH2)3Si(OEt)3] and [HC≡C(C6H4)–N(H)C(=O)N(H)(CH2)3Si(OEt)3] have been synthesized using literature methods. These have been reacted with Fe3(CO)12, Ru3(CO)12 and Co2(CO)8. With the iron carbonyl only decomposition was observed: with Ru3(CO)12 splitting of the alkynes into their parent components and formation of the complexes (μ-H)Ru3(CO)9[HC=N(CH2)3Si(OEt)3], (μ-H)Ru3(CO)9[C–C(C6H4)NH2] and (μ-H)2Ru3(CO)9[HC–CCH3] occurred. Finally, with Co2(CO)8 formation of complexes Co2(CO)6(HC2R) R=(C6H4)NH2, CH2NH(CO)NH(CH2)3Si(OEt)3, (C6H4)NH(CO)NH(CH2)3Si(OEt)3 containing the intact alkynes could be obtained.  相似文献   

14.
The polymetallic [Ru3O(CH3COO)6(py)2(BPE)Ru(bpy)2Cl](PF6)2 complex (bpy = 2,2′-bipyridine, BPE = trans-1,2-bis(4-pyridil)ethylene and py = pyridine) was assembled by the combination of an electroactive [Ru3O] moiety with a [Ru(bpy)2(BPE)Cl] photoactive centre, and its structure was determined using positive ion electrospray (ESI-MS) and tandem mass (ESI-MS/MS) spectrometry. The [Ru3O(CH3COO)6(py)2(BPE)Ru(bpy)2Cl]2+ doubly charged ion of m/z 732 was mass-selected and subject to 15 eV collision-induced dissociation, leading to a specific dissociation pattern, diagnostic of the complex structure. The electronic spectra display broad bands at 409, 491 and 692 nm ascribed to the [Ru(bpy)2(BPE)] charge-transfer bands and to the [Ru3O] internal cluster transitions. The cyclic voltammetry shows five reversible waves at −1.07 V, 0.13 V, 1.17 V, 2.91 V and −1.29 V (vs SHE) assigned to the [Ru3O]−1/0/+1/+2/+3 and to the bpy0/−1 redox processes; also a wave is observed at 0.96 V, assigned to the Ru+2/+3 pair. Despite the conjugated BPE bridge, the electrochemical and spectroelectrochemical results indicate only a weak coupling through the π-system, and preliminary photophysical essays showed the compound decomposes under visible light irradiation.  相似文献   

15.
Phase equilibria in the Ca3(VO4)2-K3VO4-NdVO4 system have been studied. An extensive calcium orthovanadate-based solid solution was found to form with the boundary compositions as follows: Ca3(VO4)2-Ca9Nd(VO4)7-Ca9.33K2.33(VO4)7-Ca7.88K2.63Nd0.87(VO4)7. The unit cell parameters of the whit-lockite vanadates synthesized increase as the potassium and neodymium contents increase. Phase transitions from the low-temperature β phase to the β′ centrosymmetrical structure in Ca9.33 − 5z K2.33 + z Nd3z (VO4)7 vanadates have been studied dilatometrically. The increase in the β ai β′ transition temperature caused by potassium is interpreted as arising from the filling in of vacant cation positions M(4) and M(6).  相似文献   

16.
A novel Ni(II) complex, [Ni(Phen)2(H2O)2][Ni(PtcH)2] · 11H2O (Phen = 1,10-phenanthroline, PtcH = pyridine-2,4,6-tricarboxylic acid), has been synthesized and characterized by elemental analysis, FT-IR, fluorescence spectrum, TGA, and single-crystal X-ray diffraction. The complex is assembled together via strong π...π and CH...π interactions, forming a 2D metal complex framework with hydrophilic cavities. In the crystal host, a novel 3D water network was enveloped, which was constructed by 1D water tapes containing adamantane-type (H2O)24 water cluster.  相似文献   

17.
The neutral dinuclear iron nitrosyl complex [Fe2(SC3H5N2)2(NO)4] (1) of the “g = 2.03” family with a ligand analogous to natural mercaptohistidine was synthesized by the metathesis reaction of the thiosulfate ligands in the [Fe2(S2O3)2(NO)4]2− anion with imidazolidine-2-thiolate ligands. The electrochemical determination of nitrogen oxide in solution showed that compound 1 has a lower NO-donor ability compared to the iron complexes with 1-methylimidazole-2-thiol and imidazole-2-thiol synthesized earlier. Study of the magnetic properties of polycrystals of 1 demonstrated that the effective magnetic moment at room temperature is ca. 2.45 μB and corresponds to a molecule containing a pair of the noninteracting spins S = 1/2. This is evidence that each iron coordination unit in complex 1 contains one unpaired electron, and the iron atom is in the low-spin state. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 28–34, January, 2007.  相似文献   

18.
The reactions of [Pd(Hdmpz)4](OOCR)2 (R = Me, Bu t , Ph, Hdmpz = 3,5-dimethylpyrazole) with the heterometallic acetate Pd(μ-OOCMe)4Co(NCMe) gives pyrazolate-bridged dimers Pd2(μ-dmpz)2(Hdmpz)2(OOCR)2 (R = Me, Bu t , Ph), which were characterized by X-ray diffraction.  相似文献   

19.
Reaction of PPh2H with Pd(PPh3)4 in a 4:1 molar ratio produced the Pd complex with two diphenylphosphine ligands, Pd(PPh2H)2(PPh3)2 (1). Complex (1) was characterized by n.m.r. (1H and 31P{1H}) spectra as well as by elemental analysis. Reaction of (1) with RhCl(PPh3)3 yielded a Pd–Rh heterobimetallic complex with bridging phosphide ligands, formulated as [(Ph3P)2Pd(μ-PPh2)2Rh(PPh3)2]Cl (2).  相似文献   

20.
Summary.  Single crystals of MgAl2F8(H2O)2 have been obtained under hydrothermal conditions (250°C, 14 d) from a starting mixture of AlF3 and MgAlF5(H2O)2 in a 5% (w/w) HF solution. The crystal structure has been determined and refined from single crystal data (Fmmm (#69), Z = 4, a = 7.2691(7), b = 7.0954(16), c = 12.452(2) ?, 281 structure factors, 27 parameters, R(F 2 > 2σ (F 2)) = 0.0282, wR(F 2 all) = 0.0885). The obtained crystals were systematically twinned according to (010/100/001) as twinning matrix, reflecting the pseudo-tetragonal metric. The crystal structure is composed of perowskite-type layers built of corner sharing AlF6 octahedra with an overall composition of AlF4 − which are connected via common fluorine atoms of [MgF4/2(H2O)2/1] octahedra. Group-subgroup relations of MgAl2F8(H2O)2 to WO3(H2O)0.33 and to other M(II)M(III)2 F8(H2O)2 structures are briefly discussed. Above 570°C, MgAl2F8(H2O)2 decomposes under elimination of water into α-AlF3, β-AlF3, and MgF2. Received October 29, 2001. Accepted (revised) December 6, 2001  相似文献   

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