{Sn9[Si(SiMe3)3]3}− and {Sn8Si[Si(SiMe3)3]3}−: variations of the E9 cage of metalloid group 14 clusters

The disproportionation reaction of the subvalent metastable halide SnBr proved to be a powerful synthetic method for the synthesis of metalloid cluster compounds of tin. Hence, the neutral metalloid cluster compound Sn(10)[Si(SiMe(3))(3)](6) (3) was synthesized from the reaction of SnBr with LiSi(SiMe(3))(3). In the course of the reaction anionic clusters might also be present, and we now present the first anionic cluster compound {Sn(8)E[Si(SiMe(3))(3)](3)}(-) (E = Si, Sn), where one position in the cluster core is occupied by a silicon or a tin atom, giving further insight into structural variations of E(9) cages in metalloid group 14 cluster compounds.     

Hydrothermal synthesis of a mixed-valence hexamolybdate cluster: crystal structure of [HN(CH2CH2)3N]2[HMoVMoVI5O19]·[N(CH2CH2)3N]

The hydrothermal reaction of MoO₃, V, Na₂WO₄· 2H₂O, [N(CH₂CH₂)₃N](1,4-diazabicyclo[2.2.2] octane), and H₂O at 160°C for 90h gave dark-brown crystals of [HN(CH₂CH₂)₃N]₂[HMo^VMo^VI ₅O¹⁹]·[N(CH₂CH₂)₃N], (1), in 40% yield. Complex (1) is the first one-electron reduced mixed-valence hexamolybdate to be crystallized and structurally characterized. The crystal structure of (1) consists of discrete [HMo^VMo^VI ₅O₁₉]^2– anions, [HN-(CH₂CH₂)₃N]⁺ cations, and neutral [N(CH₂CH₂)₃N] molecules of crystallization.     

Synthesis and characterisation of [tris(1,3-dithiole-2-thione-4,5-dithiolato)-stannate]2−, [Q]2[Sn(dmit)3], [tris(1,3-dithiole-2-one-4,5-dithiolato)stannate]2−, [Q]2[Sn(dmio)3] and [tris(1,3-dithiole-2-thione-4,5-selenolato)stannate]2−, [Q]2[Sn(dsit)3], complexes: Analysis of the structural variations of the [Sn(dmit)3]2− and [Sn(dmio)3]2− dianions

[Tris(1,3-dithiole-2-thione-4,5-dithiolato)stannate]²⁻, [Q]₂[Sn(C₃S₅)₃], [tris(1,3-dithiole-2-one-4,5-dithiolato)stannate]²⁻, [Q]₂[Sn(C₃S₄O)₃], and [tris(1,3-dithiole-2-thione-4,5-diselenolato)stannate]²⁻ [Q]₂[Sn(C₃S₃Se₂)₃], complexes, have been synthesised and characterised. Crystal structure determinations of [Q]₂[Sn(C₃S₅)₃] (Q=1,4-dimethylpyridinium, monoclinic and orthorhombic forms; NMe₄, NEt₄, and PPh₄) and [NEt₄]₂[Sn(C₃S₄O)₃] revealed variations in the overall dianion structures. The geometry about tin in each case is essentially octahedral with the chelate bite angles in the range 80.7(5)–87.45(4)°: the range of Sn–S distances is 2.5207(18)–2.571(17) Å. A statistical analysis, carried out on the crystal structure data for the six complexes, indicated that the most critical factors in controlling the overall shape of the dianion were the distances of the Sn atom from the dithiolate ligand planes [Sn–OOP]. Interanionic S⋯S interactions, within the sum of the van der Waals’ radii for two S atoms, are affected by the size of the cation, Q; the secondary connectivity is 3-dimensional for the smallest cations, Q=1,4-dimethylpyridinium and NMe₄, in chains for the somewhat larger cation, NEt₄ and is absent for the still larger, PPh₄ cation.     

(Me3Si)2CH]2(i)PrSi(NHC)Si═Si(Me)Si(i)Pr[CH(SiMe3)2]2]+: a molecule with disilenyl cation character

Reaction of the disilyne-NHC complex 1 [RLSi═SiR: (R = Si(i)Pr[CH(SiMe(3))(2)](2), L = NHC)] with MeOTf gave the cation 2 [RLSi═SiRMe](+), which is the first example of a base-stabilized heavy group 14 element analogue with vinyl cation character. Cation 2 has been fully characterized by multinuclear NMR spectroscopy and X-ray diffraction analysis. The molecular structure indicates that there are significant contributions from the NHC-stabilized cationic resonance structure 2A, the disilene-like structure 2B, and even some contribution from the silylene-like structure 2C.     

Synthesis and X-ray diffraction study of cs3[UO2(CH3COO)3]2[UO2(CH3COO)(NCS)2(H2O)] and Cs5[UO2(CH3COO)3]3[UO2(NCS)4(H2O)] · 2H2O

Cs₃[UO₂(CH₃COO)₃]₂[UO₂(CH₃COO)(NCS)₂(H₂O)] (I) and Cs₅[UO₂(CH₃COO)₃]₃[UO₂ (NCS)₄(H₂O)] · 2H₂O (II) have been synthesized via the reaction between uranyl acetate and cesium thiocyanate in aqueous solution. According to single-crystal X-ray diffraction data, both compounds crystallize in monoclinic system with the unit cell parameters a = 18.7036(5) Å, b = 16.7787(3) Å, c = 12.9636(3) Å, β = 92.532(1)°, space group C2/c, Z = 4, R = 0.0434 (I); and a = 21.7843(3) Å, b = 24.6436(5) Å, c = 13.1942(2) Å, β = 126.482(1)°, space group Cc, Z = 4, R = 0.0273 (II). Uranium-containing structural units of compound (I) are mononuclear [UO₂(CH₃COO)₃]^? and [UO₂(CH₃COO)(NCS)₂(H₂O)]^? moieties, which correspond to the AB ₃ ⁰¹ and AB⁰¹M ₃ ¹ crystallochemical groups (A = UO ₂ ²⁺ , B⁰¹ = CH₃COO^?, M¹ = NCS^? and H₂O). The structure of compound II is built of [UO₂(CH₃COO)₃]^? and [UO₂(NCS)₄(H₂O)]^2? complexes, which belong to the AB ₃ ⁰¹ and AM ₅ ¹ crystallochemical groups, respectively. Uranium-containing complexes in both structures are linked into a framework by hydrogen bonds and electrostatic interactions with cesium cations. The IR spectra of compounds I and II agree well with X-ray diffraction data.     

Substituted derivatives of tris(butadiene)-molybdenum and -tungsten; the molecular structures of (CH2CMeCMeCH2)3M (M = Mo,W)

Tris(substituted butadiene) complexes of molybdenum and tungsten have been prepared by the reduction of the metal halides with anthracene-activated magnesium in the presence of the appropriate diene. An X-ray diffraction study has shown tris(2,3-dimethylbutadiene)molybdenum and its tungsten analogue to be isomorphous, with each diene unit displaying a long—short—long bond alternation, and having short metal to terminal carbon atom distances, in marked contrast to the unsubstituted complexes.     

Synthesis and Crystal Structure of (CH2)3(3, 5-Me2Pz)2·[PhBr2Sn(CH2)SnBr2Ph]·2HBr·2H2O (Pz = pyrazole)

The reaction of bis(dibromophenylstannyl)methane with 1, 3-bis(3, 5-dimethyl- pyrazol-1-yl)propane in a 1:1 or 1:2 ratio yields only 1:1 adduct which partly hydrolyzes to the title complex (C26H38Br6N4O2Sn2, Mr = 1155.42) during crystal growing. The title complex is of triclinic, space group P ī with a = 10.886(1), b = 12.508(1), c = 13.879(1) ?, α = 85.762(2), β = 85.159(2), γ = 84.020(2)°, V = 1868.8(4) ?3, Z = 2, Dc = 2.046 g/cm3, λ(MoKα) = 0.71073 ?, μ = 7.778 mm-1, F(000) = 1088, R = 0.0488 and wR = 0.1157 for 7560 observed reflections with I ≥ 2σ(I). The crystal structure analysis indicates that there is no direct interaction between the ligand and bis(dibromophenylstannyl)methane, and two tin atoms are bridged by two bromide atoms from the partial hydrolysis of this adduct.     

Insertion reactions of [Pt(PPh3)2] fragments into the four-membered ring complex [W(CO)5PPhC(OEt)CPhCHPh]. Crystal and molecular structures of [Pt(dppe)PPh(W(CO)5)C(OEt)CPhCHPh] and [Pt(PPh3)2((W(CO)5)PhPC(OEt)CPhCHPh)(η2-PC))]

Insertion of platinum bis(phosphane) fragments into a 1,2-dihydrophosphete ring lead to complexes derived from a 1-phosphabuta-1,3-diene species.     

Reaction of chlorine with platinum(IV) triamine containing N,N-dimethylethylenediamine. The crystal structure of [Pt{(CH3)2N(CH2)2NH2}PyCl3]Cl·H2O[Pt{(CH3)2N(CH2)2NCl}PyCl3], and [Pt{(CH3)2N(CH2)2NH2}PyCl4]

The Platinum(II) diamine with N,N-dimethylethylenediamine (N,N-dimeEn) [Pt{(CH₃)₂N(CH₂)₂NH₂}Cl₂] (I) was synthesized. The reaction of the diamine with pyridine gave Pt(II) tetramine [Pt{(CH₃)₂N(CH₂)₂NH₂}Py₂]Cl₂ (II), which was oxidized with chlorine to give Pt(IV) triamine Pt{[(CH₃)₂N(CH₂)₂}PyCl₃]Cl · H₂O (III). The reaction of III with chlorine (chloroamidation) yielded chloroimide [Pt{(CH₃)₂N(CH₂)₂NCl}PyCl₃] (IV). The IR spectra of complexes I–IV and UV/Vis spectra of III and IV were studied. X-Ray diffraction analysis was performed for III (monoclinic crystals, space group P2₁/c, a = 7.7437(6), b = 8.1100(7), c = 28.52992(2) Å, β = 93.7280(10)°, Z = 4, R _hkl = 0.0420) and IV (orthorhombic crystals, space group Pna2₁, a = 15.7825(12), b = 7.4447(6), c = 12.3099(6) Å, Z = 4, R _hkl = 0.0539). During oxidation of Pt(II) tetramine with chlorine, the pyridine molecule is removed from the cis position relative to the (CH₃)₂N group (trans position relative to the NH₂ group) of N,N-dimethylethylenediamine. The reaction of chloroimide complex IV with concentrated HCl (dechloroamidation) at 20°C afforded the initial complex III; that at 100°C, gave triamine III together with Pt(IV) diamine [Pt(N,N-dimeEn)Cl₄] (V) (monoclinic crystals, space group P2₁/n, a = 7.1278(5), b = 11.5384(8), c = 12.7501(9) Å, β = 93.23(10)°, Z = 4, R _hkl = 0.0239).     

Synthesis and Structure of [HOCH2CH2N（CH3）3]4[Cu4OCl10]

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Synthesis and structure of [Cr3O(CH3COO)6(H2O)3][UO2 (CH3COO)3] · 3H2O

Crystals of [Cr₃O(CH₃COO)₆(H₂O)₃][UO₂(CH₃COO)₃]·3H₂O (I) were synthesized for the first time and studied by X-ray crystallography. The crystals of I are orthorhombic: a = 8.3561(3) ?, b = 16.8421(5) ?, c = 25.7448(9) ?, V = 3623.2(2) ?³, space group P2₁2₁2₁, Z = 4, R = 0.0409. The structure is composed of trinuclear [Cr₃O(CH₃COO)₆(H₂O)₃]⁺ complexes and mononuclear [UO₂(CH₃COO)₃]^? complexes classified with crystal-chemical groups A₃M³B ₆ ² M ₃ ¹ (A = Cr³⁺, M³ = O^2?, B² = CH₃COO^?, M¹ = H₂O) and AB ₃ ⁰¹ (A = UO ₂ ²⁺ , B⁰¹ = CH₃COO^?), respectively. The complexes are bound to each other by electrostatic interactions and hydrogen bonds involving outer-sphere water molecules. The results of IR spectroscopic study of I are in good agreement with the structural data for the crystal.     

Synthesis of the five-coordinate organoplatinum cation [PtMe(pp3)]+ (pp3 =P(CH2CH2PPh2)3) by oxidative addition of methyl iodide to [Pt2(μ-pp3)2]

The complex [Pt₂(μ-pp₃)₂] (pp₃ = P(CH₂CH₂PPh₂)₃), produced by treatment of [PtH(pp₃)]⁺ with sodium amalgam, has been shown to react with methyl iodide to give [PtMe(pp₃)]⁺. The new complexes have been characterized by ¹H, ³¹P and ¹⁹⁵Pt NMR spectroscopy.     

Heteronuclear (WFe) and homonuclear (FeFE) μ-alkylidene complexes of transition metals from mononuclear terminal carbene complexes. crystal structures of {WFe[μ-η1, η3-C(OCH2CH3)(CHCHCH3](CO)8} and [fe2{μ-η2,η3-C[OCH2CH3[CHC(OCH2CH3)(CH3]}(CO)6

The reactions of mononuclear carbene complexes of W and Fe of the type CO)_mMC(OR)(CH_2nCHCR′″ (M  = FE, W; m = 4 and 5; n = 0, 2, 3; R′, R″ = C, CH₃, OEt) with Fe(CO)₅ have been studied. In all cases the reaction leads to new hetero (WFe) or homo (FeFe) μ-alkylidene complexes, the position of the double bond depending strongly on n.     

Chlorine reaction with platinum triamine [Pt(N,N-DimeTm)PyCl3]Cl (N,N-DimeTm = (CH3)2N(CH2)3NH2). Crystal structure of [Pt(N,N-DimeTm)Cl2], [Pt(N,N-DimeTm(Py)Cl3]Cl · H2O and [Pt{(CH3)2N(CH2)2C(O)NH}(Py)Cl3]

Treatment of platinum(II) diamine [Pt(N,N-DimeTm)Cl₂] (I) with pyridine gave tetramine [Pt(N,N-DimeTm)Py₂]Cl₂ (II); by oxidation with chlorine this was converted to Pt(IV) triamine, [Pt“(N,N-DimeTm(Py)Cl₃]Cl (III) with a six-membered chelate ring. According to X-ray diffraction data, the reaction of complex II with chlorine is accompanied by removal of the pyridine molecule from the trans-position to the NH₂ group of N,N-dimethyltrimethylenediamine. The reaction of complex III with chlorine at 20°C afforded a mixture of compounds (IV) and the complex [Pt“(CH₃)₂N(CH₂)₂C(O)NH”(Py)Cl₃] (V) with an amidate six-membered metal ring, dimethylpropioamide, which was also isolated upon refluxing a mixture of IV in an aqueous solution. The UV/Vis and IR spectra of the obtained complexes were studied, and X-ray diffraction analysis of I, III, and V was performed. The crystals of I are triclinic, space group P $ \bar 1 $ ; a = 7.6526(4) Å, b = 11.5571(6) Å, c = 12.4432(7) Å, α = 113.85(1)°, β = 96.54(2)°, γ = 106.78(2)°; Z = 4; R _hkl = 0.051. The crystals of III are monoclinic, space group C2/c; a = 36.715(2) Å, b = 7.8179(4) Å, c = 29.721(16) Å, β = 127.80(1)°; Z = 16; R _hkl = 0.036. The crystals of V are monoclinic, space group P2₁/n; a = 7.0398(6) Å, b = 27.458(2) Å, c = 7.687(6) Å, β = 106.270(1)°; Z = 4; R _hkl = 0.052.     

反常蓝移单电子锂键Y…Li-CH3[Y=CH3, CH2CH3, CH(CH3)2, C(CH3)3]体系的结构与性质

在密度泛函理论B3LYP/6-311++G(d,p)及MP2/6-311++G(d,p)水平上研究了单电子锂键复合物Y…Li—CH3[Y=CH3, CH2CH3, CH(CH3)2, C(CH3)3]的结构与性质. 结果表明, 三种单电子锂键复合物H3CH2C…Li—CH3(II), (H3C)2HC…Li—CH3(III)和(H3C)3C…Li—CH3(IV)单电子锂键强度依II(-26.7 kJ·mol-1)相似文献   

Pulsed NMR study of molecular motions and phase transitions in [N(CH3)4]PbX3 (XCl,Br, I)

Proton spin—lattice relaxation time (T₁) is measured in [N(CH₃)₄]PbX₃ (XCl, Br, I) from 300-77 K at 9.75 MHz. All the compounds show discontinuous changes in T₁ values (at 256, 270 and 277 K, respectively), indicating phase transitions. Single T₁ minimum is observed in all the cases and the T₁ variation is explained in terms of [N(CH₃)₄] and CH₃ group dynamics. The activation energy E_α decreases from chloride to iodide (from 4 to 2 kcal/mol). In bromide and iodide, T₁ is found to decrease with increase in temperature at higher temperatures, indicating the presence of spin—rotation interaction.     

[Sn 2 (H 2 O) 2 Br 2 (CH 3 ) 4 {μ-(CH 2 ) 3 }·2bpy]: A Layered,Hetero Bimolecular Composite (bpy=2,2′-bipyridine)

Reaction of (Me 2 SnBr) 2 w -(CH 2 ) 3 with 2,2'-bipyridine (bpy) in benzene affords, in the presence of small amounts of water, crystals of the novel composite [Sn 2 (H 2 O) 2 Br 2 Me 4 { w -(CH 2 ) 3 }2bpy] ( 1 ). The crystal structure of 1 consists of alternating layers of either organotin bromide or bipyridine molecules, each bpy molecule being configured cis oid and linked with the organotin layer via one O-H > N hydrogen bond. The mutual disposal of the molecules in the bpy bilayer differs from that known for pure, crystalline bpy. Cell parameters: a 24.3499(1), b 6.5112(1), c 23.3262(1) Å; g 119.557(1). Monoclinic, space group C 2/ c , D calc =1.750 g/cm 3 , Z =4; final R 1: 0.0529; wR 2=0.1374 for 3638 unique reflections [ R (int)=0.0676; I >2 ( I )].     

Structure of [NH3(CH2)4NH3]2P4O12·2H2O

After a short survey of what is the present state of the cyclophosphates associated with the organic molecule NH₂(CH₂)₄NH₂, we report chemical preparation and crystal structure for a new example of such compounds. [NH₃(CH₂)₄NH₃]₂P₄O₁₂.2H₂O is monoclinic (S.G. : P2₁/n), with Z = 2 and the following unit-cell parameters : a = 7.6728(8) Å, b = 18.962(3) Å, c = 7.9789(9) Å β = 111.751(9)°. Bidimensional layer arrangement of P₄O₁₂ rings connected to the water molecules thanks to weak H-bonds run parallel to the ab plane. The organic groupements located between these inorganic planes perform the three-dimensional cohesion by NH····O hydrogen bonds.