Cubane Tellurido Clusters [Zn(NH3)4]3[Mo4Te4(CN)12] and [Cd(NH3)4]3[W4Te4(CN)12]: Syntheses and Crystal Structures

Single crystals of [Zn(NH₃)₄]₃[Mo₄Te₄(CN)₁₂] (I) and [Cd(NH₃)₄]₃[W₄Te₄(CN)₁₂] (II) were obtained by applying solutions of K₇[Mo₄Te₄(CN)₁₂] · 11H₂O and K₆[W₄Te₄(CN)₁₂] · 5H₂O in aqueous ammonia over solutions of ZnCl₂ and Cd(NO₃)₂ in glycerol and were characterized by X-ray diffraction analysis. The IR spectra and thermal properties of compounds I and II were examined.     

Fluorination of [Os3(CO)12] and [Ir4(CO)12

Fluorination of [Os(3)CO(12)] in HF/SbF(5) affords [Os(CO)(4)(FSbF(5))(2)]. According to its crystal structure (orthorhombic, Pna2(1), a = 1590.3(3), b = 1036.6(1), c = 878.2(2) pm, Z = 4), the two SbF(6) units occupy cis positions in the octahedral environment around the Os atom. Fluorination of [Ir(4)(CO)(12)] in HF/SbF(5) produced three different compounds: (1) [Ir(4)(CO)(8)(mu-F)(2)(Sb(2)F(11))(2)] (tetragonal, P4n2, a = 1285.2(2), c = 952.9(1) pm, Z = 2). Here, two of the six edges of the Ir(4) tetrahedron in [Ir(4)CO(12)] are replaced by bridging fluorine atoms. (2) [fac-Ir(CO)(3)(FSbF(5))(2)HF]SbF(6).HF (orthorhombic, Pnma, a = 1250.6(1), b = 1340.7(2), c = 1092.6(2) ppm, Z = 4). The Ir(4) tetrahedron in Ir(4)(CO)(12) is completely broken down, but the facial Ir(CO)(3) configuration is retained. (3) [mer-Ir(CO)(3)F(FSbF(5))(2)] (triclinic, P1, a = 834.9(1), b = 86 4.9(1), c = 1060.0(1) pm, alpha = 69.173(4) degrees, beta = 77.139(4) degrees, gamma = 88.856(4) degrees, Z = 2).     

Synthese und Kristallstrukturen von (PPh4)2[In(S4)(S6)Cl] und (PPh4)2[In(S4)Cl3]

Synthesis and Crystal Structures of (PPh₄)₂[In(S₄)(S₆)Cl] and (PPh₄)₂[In(S₄)Cl₃] InCl and PPh₄Cl yield (PPh₄)₂[In₂Cl₆] in acetonitrile. This reacts with Na₂S₄ in presence of PPh₄Cl, forming (PPh₄)₂[In(S₄)(S₆)Cl]. Its crystal structure was determined by X-ray diffraction (R = 0.075, 2 282 observed reflexions). It is isotypic with (PPh₄)₂[In(S₄)(S₆)Br] and contains anions with trigonal-bipyramidal coordination of In, Cl occupying an axial position, and the S₄ and S₆ groups being bonded in a chelate manner. The reaction of (PPh₄)₂[In₂Cl₆] and sulfur in acetonitrile yielded (PPh₄)₂[InCl₅] and (PPh₄)₂[In(S₄)Cl₃]. The crystal structure analysis of the latter (R = 0.072, 4 080 reflexions) revealed an anion with distorted trigonal-bipyramidal coordination of In, the S₄ group occupying one axial and one equatorial position; the S₄ group shows positional disorder.     

Die Kristallpackung in drei Modifikationen von PPh4[ReO(S4)2] und PPh4[ReS(S4)2]

The Crystal Packing in three Modifications of PPh₄[ReO(S₄)₂] and PPh₄[ReS(S₄)₂] Mixed crystals PPh₄[ReS(S₄)₂]_0,63[ReO(S₄)₂]_0,37 were obtained from PPh₄Cl, ReCl₅ and Na₂S₄ in acetonitrile. Their crystal structure corresponds to the known structure of this kind of compound (space group P2₁/n). In a similar reaction with ReBr₅ instead of ReCl₅, PPh₄[ReO(S₄)₂] was obtained in small yield. Its triclinic crystal structure was determined by X‐ray crystallography (space group P1). It contains cation pairs (PPh₄⁺)₂ such as they have been found in many other instances. In contrast, the crystal structures of the mixed crystals and of one known modification of PPh₄[ReS(S₄)₂] have PPh₄⁺ columns similar to compounds crystallizing in the space group P4/n, albeit in a severely distorted manner; their space group P2₁/n is a subgroup of P4/n with a doubled unit cell. In another modification of PPh₄[ReS(S₄)₂] (space group P2₁/c) the columns are less distorted, but arranged in a different way.     

[Cu12(NPEt3)8]4+ and [Ag12(NPEt3)8]4+: Cubane Structures

Unusual, highly symmetrical cubes are formed by the dodecameric cationic phosphoraneiminato complexes of copper(I ) and silver(I ) [M₁₂(NPEt₃)₈]⁴⁺, in which the metal atoms occupy the edges and the N atoms of NPEt ³⁻₃ groups the corners of the cube (see figure). The structures can be understood as molecular sections of the Cu₃N structure, which is inverse to the ReO₃‐type structure.     

二铁氧还盐和四铁氧还盐的电子结构

本文采用CNDO/2-SD方法计算了二铁氧还盐及四铁氧还盐的电子结构.与Roussin 红盐及Roussin 黑盐的电子结构比较,相似之处为:在铁局部对称性为四面体的簇合物中, Fe-Fe间相互作用主要由铁的s,p电子的σ贡献产生, 金属d轨道的π相互作用在占有轨道区间同时具有成键和反键贡献, 因而对骨架的形成几乎无贡献. 骨架μ2-S桥含有孤对电子,有形成μ3-S桥的可能, 但以桥硫孤对电子贡献为主的轨道都不是前线轨道. 不同之处在于端基为SH的簇合物骨架电子的非定域性较端基为NO时更强. 二核簇合物Fe与端基SH的成键能力比与NO的小, 因而在自兜反应中容易失去端基SH而形成封闭型结构.     

Synthese und Kristallstrukturen von (PPh4)2[As2Se4Cl12] und (PPh4)2[As2Se4Br12]

Synthesis and Crystal Structures of (PPh₄)₂[As₂Se₄Cl₁₂] and (PPh₄)₂[As₂Se₄Br₁₂] The reaction of PPh₄Cl and As₂Se₃ with SOCl₂ or with chlorine in dichloromethane affords (PPh₄)₂[As₂Se₄Cl₁₂] with good yields. From PPh₄Br, As₂Se₃ and bromine the corresponding bromo compound was obtained. According to the X-ray crystal structure determinations both compounds are isotypic, crystallizing in the space group of P1 . In the anions two Se₂X₂ molecules are linked with two X^? ions forming an Se₄X₂ ring in chair conformation. Each X^?-ion is associated with an additional AsX₃ molecule (X = Cl, Br).     

Sequential oxidation of the cubane [4Fe--4S] cluster from [4Fe--4S](-) to [4Fe--4S](3+) in Fe(4)S(4)L(n)(-) complexes

Gaseous Fe(4)S(n)(-) (n = 4-6) clusters and synthetic analogue complexes, Fe(4)S(4)L(n)(-) (L = Cl, Br, I; n = 1-4), were produced by laser vaporization of a solid Fe/S target and electrospray from solution samples, respectively, and their electronic structures were probed by photoelectron spectroscopy. Low binding energy features derived from minority-spin Fe 3d electrons were clearly distinguished from S-derived bands. We showed that the electronic structure of the simplest Fe(4)S(4)(-) cubane cluster can be described by the two-layer spin-coupling model previously developed for the [4Fe] cubane analogues. The photoelectron data revealed that each extra S atom in Fe(4)S(5)(-) and Fe(4)S(6)(-) removes two minority-spin Fe 3d electrons from the [4Fe--4S] cubane core and each halogen ligand removes one Fe 3d electron from the cubane core in the Fe(4)S(4)L(n)(-) complexes, clearly revealing a behavior of sequential oxidation of the cubane over five formal oxidation states: [4Fe--4S](-) --> [4Fe--4S](0) --> [4Fe--4S](+) --> [4Fe-4S](2+) --> [4Fe-4S](3+). The current work shows the electron-storage capability of the [4Fe--4S] cubane, contributes to the understanding of its electronic structure, and further demonstrates the robustness of the cubane as a structural unit and electron-transfer center.     

Synthese und Kristallstrukturen von (NEt4)2[TeS3], (NEt4)2[Te(S5)(S7)] und (NEt4)4[Te(S5)2][Te(S7)2]

Synthesis and Crystal Structures of (NEt₄)₂[TeS₃], (NEt₄)₂[Te(S₅)(S₇)], and (NEt₄)₄[Te(S₅)₂][Te(S₇)₂] (NEt₄)₂[TeS₃] was obtained by the reaction of NEt₄Cl, Na₂S₄ and tellurium in acetonitrile. It reacts with sulfur, yielding (NEt₄)₂[Te(S₅)(S₇)], which is transformed to (NEt₄)₄[Te(S₅)₂][Te(S₇)₂] by recrystallization from hot acetonitrile. According to the X-ray structure analysis, crystals of (NEt₄)₂[TeS₃] are monoclinic (space group P2₁/c) and form twins with the twinning plane (001); they contain pyramidal TeS₃^2– ions. (NEt₄)₂[Te(S₅)(S₇)] forms triclinic twins (space group P1) with the twinning plane (010). In the [Te(S₅)(S₇)]^2– ion an S₅ and an S₇ atom group are bonded in a chelate manner to the tellurium atom, which has square coordination. (NEt₄)₄[Te(S₅)₂][Te(S₇)₂] (monoclinic, space group P2₁/c) contains two kinds of anions, the known [Te(S₅)₂]^2– and the new [Te(S₇)₂]^2– ion which has two S₇ chelating groups.     

[Mo12S12O12(OH)12(H2O)6]: A Cyclic Molecular Cluster Based on the [Mo2S2O2]2+ Building Block

The pH-dependent self-condensation of the [Mo ₂ S ₂ O ₂ ] ²⁺ complex fragment gives the wheellike Mo₁₂ cluster depicted on the right (ball-and-stick model; large balls: S, medium balls: O, small balls: Mo). Applying this synthetic strategy to other starting materials could provide access to other polyoxothiometalates with well-defined cavities.     

Characterization of Diastereoisomeric [Ni(Me8[14]ane)]2+ Cations

The isomeric Me₈[l4]anes, designated by L_A, L_B and L_C, on reaction with nickel(II) acetate tetrahydrate and subsequent addition of LiClO₄·3HO yield yellow or orange-yellow square planar [NiL](ClO₄)₂ diastereoisomers. It has been possible to isolate two N-chiral diastereoisomers for each ligand and these give distinct infrared and ¹H NMR spectra. The structures of these isomers have been assigned mainly on the basis of their ¹H NMR spectra. One structure, namely [NiL_Bα ](ClO₄)₂, has been confirmed by x-ray crystallography.