Structural Characterization of trans-[Cr(NH3)4(H2O)Cl]Cl2 and trans-[Cr(NH3)4Cl2]l

Trans-[Cr(NH₃)₄(H₂O)Cl]Cl₂ (A) crystallizes in the monoclinic space group P2₁/m (No. 11) with a = 6.556(1), b = 10.630(5), c = 6.729(2) Å and β = 96.15(3)°. Trans-[Cr(NH₃)₄Cl₂]I (B) has monoclinic C2/m (No. 12) space group and a = 9.877(2), b = 8.497(2), c = 6.047(2) Å and β = 108.98(2)°. Both unit cells contain two formula units. Cr? Cl, Cr? O(H₂O) and three independent Cr? N(NH₃) distances for A are 2.98(1), 2.023(2), 2.067(2), 2.086(3) and 2.064(3) °. Cr? Cl and Cr? N(NH₃) bonds in B are 2.325(1) and 2.071(2) °. All octahedral angles are close to 90 and 180°. Both structures were refined to very low R values. Water molecule from trans-[Cr(NH₃)₄(H₂O)Cl]²⁺ is hydrogen bonded to both ionic chlorides. Cation and two anions form the motive which repeats itself in the crystal. Cations and anions of the second structure are distributed in layers. Each cation and anion have coordination number eight.     

Fixation of Metallo Nitrile Ylides and Metallo Nitrile Imines as Ligands in Transition Metal Complexes [1]

1,3‐Dipoles of the type metallo nitrile ylide and metallo nitrile imine were prepared by mono‐α‐deprotonation of CH‐acidic {[W(CO)₅CHCH₂PPh₃]PF₆, M(CO)₅CNCH₂CO₂R (M = Cr, W; R = Me, Et), [Pt(Cl)(CNCH₂CO₂Et)(PPh₃)₂]BF₄} and NH‐acidic isocyanide complexes (Cr(CO)₅CNNH₂) and were stabilized by coordination to a second transition metal complex fragment {Cr(CO)₅, [M(CO)₅]⁺ (M = Mn, Re), [FeCp(CO)₂]⁺, [Pt(Cl)(PR₃)₂]⁺ (R = Et, Ph)}. All dinuclear products 1 – 7 , 10 , and 11 are neutral species except [(Ph₃P)₂(Cl)Pt{μ₂‐CNCH(CO₂Et)}Pt(Cl)(PPh₃)₂]BF₄ ( 8 ). Complex (OC)₅W{μ₂‐CNCH(CO₂Et)}Pt(Cl)(PEt₃)₂ ( 5b ) was characterized by X‐ray diffraction. Twofold deprotonation/platination to give (OC)₅Cr{μ₃‐CNC(Ph)}[Pt(Cl)(PPh₃)₂]₂ ( 9 ) was achieved in the case of Cr(CO)₅CNCH₂Ph.     

Synthese und Struktur von Ammin- und Amidokomplexen des Iridiums

Synthesis and Structure of Ammine and Amido Complexes of Iridium The reaction of (NH₄)₂[IrCl₆] with NH₄Cl at 300 °C in a sealed glass ampoule yields the iridium(III) ammine complex (NH₄)₂[Ir(NH₃)Cl₅], which crystallizes isotypically with K₂[Ir(NH₃)Cl₅] in the orthorhombic space group Pnma with Z = 4, and a = 1350.0(2); b = 1028.5(3); c = 689.6(2) pm. The reaction of (NH₄)₂[IrCl₆] with NH₃ at 300 °C, however, gives the already known [Ir(NH₃)₅Cl]Cl₂ beside a small amount of [Ir(NH₃)₄Cl₂]Cl₂. In pure form [Ir(NH₃)₅Cl]Cl₂ is obtained by ammonolysis of (NH₄)₂[Ir(NH₃)Cl₅] at 300 °C with NH₃. [Ir(NH₃)₄Cl₂]Cl₂ crystallizes triclinic (P1, Z = 1, a = 660,2(3); b = 680,4(3); c = 711,1(2) pm; α = 103,85(2)°, β = 114,54(3)°, γ = 112,75(2)°). The structure contains Cl^– anions and [Ir(NH₃)₄Cl₂]²⁺ cations with a trans position of the Cl atoms. Upon reaction of [Ir(NH₃)₅Cl]Cl₂ with Cl₂ one ammine ligand is eliminated yielding [Ir(NH₃)₄Cl₂]Cl, which is transformed to orthorhombic [Ir(NH₃)₄(OH₂)Cl]Cl₂ (Pnma, Z = 4, a = 1335,1(3); b = 1047,9(2); c = 673,4(2) pm) by crystallization from water. In the octahedral complex [Ir(NH₃)₄(OH₂)Cl]²⁺ the four ammine ligands have an equatorial position, whereas the Cl atom and the aqua ligand are arranged axial. Oxidation of (NH₄)₂[Ir(NH₃)Cl₅] with Cl₂ at 330 °C affords the tetragonal Ir^IV complex (NH₄)[Ir(NH₃)Cl₅] (P4nc, Z = 2, a = 702.68(5); c = 912.89(9) pm). Its structure was determined using the powder diagram. Oxidation of (NH₄)₂[Ir(NH₃)Cl₅] with Br₂ in water, on the other hand, gives (NH₄)₂[IrBr₆] crystallizing in the K₂[PtCl₆] type. Oxidation of (PPh₄)₂[Ir(NH₃)Cl₅] with PhI(OAc)₂ in CH₂Cl₂ affords the Ir^V amido complex (PPh₄)[Ir(NH₂)Cl₅].     

Darstellung und Kristallstruktur von (NH4)2[V(NH3)Cl5]. Die Kristallchemie der Salze (NH4)2[V(NH3)Cl5], [Rh(NH3)5Cl]Cl2 und M2VXCl5 mit M = K,NH4, Rb,Cs und X = Cl,O

Preparation and Crystal Structure of (NH₄)₂[V(NH₃)Cl₅]. The Crystal Chemistry of the Compounds (NH₄)₂[V(NH₃)Cl₅], [Rh(NH₃)₅Cl]Cl₂, and M₂VXCl₅ with M = K, NH₄, Rb, Cs and X ? Cl, O (NH₄)₂[V(NH₃)Cl₅] crystallizes like [Rh(NH₃)₅Cl]Cl₂ in the orthorhombic space group Pnma with Z = 4. The compounds are built up by isolated NH₄⁺ or Cl^? and complex MX₅Y ions. The following distances have been observed: V? N: 213.8, V? Cl: 235.8–239.1, Rh? N: 207.1–208.5, Rh? Cl: 235.5 pm. Both structures differ from the K₂PtCl₆ type mainly in the ordering of the MX₅Y polyhedra. The compounds M₂VCl₆ and M₂VOCl₅ with M = K, NH₄, Rb, and Cs crystallize with exception of the orthorhombic K₂VOCl₅ in the K₂PtCl₆ type. The ordering of the MX₅Y polyhedra in the compounds (NH₄)₂[V(NH₃)Cl₅], [Rh(NH₃)₅Cl]Cl₂ and K₂VOCl₅ enables a closer packing.     

Perfluormethyl-Element-Liganden. XL. Chrom- und Wolframpentacarbonylkomplexe von Bis(trifluormethyl)phosphanen des Typs (F3C)2PX′ (X′ = H,F, Cl,Br, I,NEt2)

Perfluormethyl-Element-Ligands. XL. Chromium and Tungsten Pentacarbonyl Complexes of Bis(trifluoromethyl)phosphanes of the Type (F₃C)₂PX′ (X′ = H, F, Cl, Br, I, NEt₂) The complexes M(CO)₅P(CF₃)₂X′ (M = Cr, W; X′ = H, F, Cl, Br, I) are obtained in preparative amounts (yields between 15 and 42%) by reacting the ligands (F₃C)₂PX′ with the adducts “M(CO)₅CH₂Cl₂”, photochemically generated from M(CO)₆ in methylene chloride. The corresponding derivatives of the aminophosphane Et₂NP(CF₃)₂ can be produced in good yields (60–75%) using the THF complexes M(CO)₅THF as precursors. The spectroscopic data (MS, IR, NMR) of the new compounds are reported. The CO valence frequencies v(CO) and the coordination shifts Δδ prove the high π-acidity of the ligands (F₃C)₂PX′.     

Rhodium complexes of PCNHCP: Oxidative addition of dichloromethane and catalytic hydrosilylation of alkynes affording (E)-alkenylsilanes

New rhodium complexes of PC^NHCP have been synthesized by using the silver transfer reagent, [Ag₃(PC^NHCP)₂Cl]Cl₂ (2). In the reaction between 2 and [Rh(COD)Cl]₂ in dichloromethane, the presumably formed nucleophilic Rh^I(PC^NHCP)Cl intermediate (A), undergoes a C–Cl bond activation of CH₂Cl₂ giving cis,mer-Rh^III(PC^NHCP)(CH₂Cl)Cl₂ (3) as the final product. Attempts to isolate A affords the oxidative degradation product of mer-Rh^III(PC^NHCP)Cl₃ complex (4). In contrast, the rhodium(I) center in Rh(PC^NHCP)(CO)Cl (5) is stabilized by the π-back bonding of CO ligand; a robust complex is, therefore, obtained. The solid-state structures of 2 and 3 were determined by X-ray diffraction. Complexes 3–5 are catalyst precursors for efficient, chemoselective hydrosilylation of alkynes. For the reaction between phenylacetylene and dimethylphenylsilane, a rapid hydrosilylation occurs, producing isomers of alkenylsilanes; then a slow isomerization pathway converts (Z)-alkenylsilane to its (E)-isomer. For 3, under catalytic condition, a facile reductive elimination of dichloromethane giving A is anticipated. The similarity in reactivity and selectivity between 3, 4 and 5 suggests the involvement of A as the active species in a common catalytic cycle.     

Syntheses and Structures of Two Selenite Chloride Hydrates: Co(HSeO3)Cl · 3 H2O and Cu(HSeO3)Cl · 2 H2O

The first selenite chloride hydrates, Co(HSeO₃)Cl · 3 H₂O and Cu(HSeO₃)Cl · 2 H₂O, have been prepared from solution and characterised by single‐crystal X‐ray diffraction. The cobalt phase adopts an unusual “one‐dimensional” structure built up from vertex‐sharing pyramidal [HSeO₃]^2–, and octahedral [CoO₂(H₂O)₄]^2– and [CoO₂(H₂O)₂Cl₂]^4– units. Inter‐chain bonding is by way of hydrogen bonds or van der Waals' interactions. The atomic arrangement of the copper phase involves [HSeO₃]^2– pyramids and Jahn‐Teller distorted [CuCl₂(H₂O)₄] and [CuO₄Cl₂]^8– octahedra, sharing vertices by way of Cu–O–Se and Cu–Cl–Cu bonds. Crystal data: Co(HSeO₃)Cl · 3 H₂O, M_r = 276.40, triclinic, space group P 1 (No. 2), a = 7.1657(5) Å, b = 7.3714(5) Å, c = 7.7064(5) Å, α = 64.934(1)°, β = 68.894(1)°, γ = 71.795(1)°, V = 337.78(7) ų, Z = 2, R(F) = 0.036, wR(F) = 0.049. Cu(HSeO₃)Cl · 2 H₂O, M_r = 263.00, orthorhombic, space group Pnma (No. 62), a = 9.1488(3) Å, b = 17.8351(7) Å, c = 7.2293(3) Å, V = 1179.6(2) ų, Z = 8, R(F) = 0.021, wR(F) = 0.024.     

Cyclic Tribismuthide as a Piano Stool Complex Ligand – Synthesis and Crystal Structure of (η3‐Bi3)M(CO)33– (M = Cr,Mo)

The reactions between K₅Bi₄, [(C₆H₆)Cr(CO)₃] or [(C₇H₈)Mo(CO)₃], and [2.2.2]crypt in liquid ammonia yielded the compounds [K([2.2.2]crypt)]₃(η³‐Bi₃)M(CO)₃ · 10NH₃ (M = Cr, Mo), which crystallize isostructurally in P2₁/n. Both contain an 18 valence electron piano‐stool complex with a η³‐coordinated Bi₃‐ring ligand. The Bi–Bi distances range from 2.9560(5) to 2.9867(3) Å and are slightly shorter than known Bi–Bi single bonds but longer than Bi–Bi double bonds. The newly found compounds complete the family of similar complexes with E₃‐ring ligands (E = P‐Bi).     

trans‐Carbonylchloridobis(ferrocenyldiphenylphosphane‐κP)rhodium(I) dichloromethane monosolvate and trans‐carbonylchloridobis(ferrocenyldiphenylphosphane‐κP)iridium(I) dichloromethane monosolvate

The isomorphous crystal structures of the title compounds, [Fe₂M(C₅H₅)₂(C₁₇H₁₄P)Cl(CO)]·CH₂Cl₂ or trans‐[MCl(CO)(PPh₂Fc)₂]·CH₂Cl₂ (M = Rh or Ir, and Fc is ferrocenyl), are reported. The data collection for M = Rh was performed at 293 (2) K, while the M = Ir data were collected at 160 (2) K. The compounds crystallize with two independent half‐molecules in the asymmetric unit, both occupying inversion centres, and are accompanied by a single dichloromethane molecule on a general position. Due to the symmetry, there is 0.50/0.50 disorder present in the chloride and carbonyl positions. One molecule in each structure also has a second type of disorder in the chloride and carbonyl positions, which was refined over another two positions of equal distribution. The steric impact of the bulky PPh₂Fc ligands was evaluated using the Tolman cone‐angle model, resulting in an average value of 172° for the four molecules in both structures.     

First example of ruthenium nitroso monoammine complex. Crystal structure of [Ru(NO)(NH3)3(H2O)Cl] × [Ru(no)(NH3)3(OH)Cl][Ru(NO)(NH3)Cl4]2Cl·2H2O

The structure of the interaction products of (NH₄)₂[Ru(NO)Cl₅] solution with ammonium acetate on heating is studied. The crystal structure of the [Ru(NO)(NH₃)₃(H₂O)Cl][Ru(NO)(NH₃)₃(OH)Cl] × [Ru(NO)(NH₃)Cl₄]₂Cl-2H₂O compound (compound I) containing a previously unknown anion of the nitrosomonoammine series is determined: Cc space group; a = 33.530(7) ?, b = 8.202(2) ?, c = 11.844(2) ?; β= 101.54(3)°.     

SYNTHESES AND REACTIONS OF THE COMPLEXES (η5-C5Me5)Re(CO)2(C6CL5–nHn)Cl (n = 2,3): COMPOUNDS DERIVED FROM INITIAL C—CI ACTIVATION

Abstract

The UV irradiation of (η⁵-C₅Me₅)Re(CO)₃ in the presence of 1,2,4,5-C₆Cl₄H₂ and 1,3,5-C₆Cl₃H₃ (λ = 350 nm, hexane solution) effected intramolecular C—Cl activation, generating the complexes trans-(η⁵-C₅Me₅)Re(CO)₂(2,4,5-C₆Cl_5-nH_n)Cl, ((1), n = 2; (2), n = 3), respectively. Complex (1) dissolved in polar organic solvents produces, an equilibrium mixture with its cis isomer. The reaction of (1) with AgBF₄, in acetonitrile, led to formation of the cationic complex [cis-(η⁵-C₅Me₅)Re(CO)₂(2,4,5-C₆Cl₃H₂)(MeCN)]⁺. The tetramethylfulvene complex (η⁶-C₅Me₄CH₂)Re(CO)₂(2,4,5-C₆Cl₃H₂) (3) was obtained by reacting the cationic complex with the fluorinating agent Et₃N′3HF.     

Heterobimetallic complexes from addition of molybdo- or tungstophosphine ligands to metal halides and by oxidative addition of molybdo- or tungsto-aryl iodides to low-oxidation state metal species

Summary Reaction of [M{HB(Me₂pyz)₃}(NO)X{NH(CH₂)₃PPh₂}] [M=Mo, X=I; M=W, X=Cl; HB(Me₂pyz)₃=tris(3,5-dimethylpyrazolyl)borate] with [Rh₂(CO)₄Cl₂], HgI₂ and CdCl₂ gave [{M{HB(Me₂pyz)₃}(NO)X[NH(CH₂)₃PPh₂]}₂-Rh(CO)Cl] and [{Mo{HB(Me₂pyz)₃}(NO)I[NH(CH₂)₃-PPh₂]}₂MX₂] (M=Hg, Y=I; M=Cd, Y=Cl). The di- or poly-meric species [Mo{HB(Me₂pyz)₃}(NO)I(p-OC₆H₄-HgCl)]_n is reported, and reaction of [Mo{HB(Me₂pyz)₃}-(NO)I(p-NHC₆ H₄I)] with [Pd(PPh₃)₄] and [Pt(C₂H₄)(PPh₃)₂] afforded [Mo{HB(Me₂pyz)₃}(NO)I{NHC₆H₄M(PPh₃)₂X}] (M=Pd, X=Br, I; M=Pt, X=I).     

A DFT study of Lp···π/halogen bond competition in complexes of perhalogenated alkenes with oxygen/nitrogen containing simple molecules

The possible noncovalent lone pair‐π/halogen bond (lp···π/HaB) complexes of perhalogenated unsaturated C₂Cl_nF_4?n (n = 0–4) molecules with four simple molecules containing oxygen or nitrogen as electron donor, formaldehyde (H₂CO), dimethyl ether (DME), NH₃, and trimethylamine (TMA), have been systematically examined at the M062X/aug‐cc‐pVTZ level. Natural bond orbital (NBO) analysis at the same level is used for understanding the electron density distributions of these complexes. The progressive introduction of Cl atom on C₂Cl_nF_4?n influences more on the lp···π complexes over the corresponding HaB ones. Within the scope of this study, gem‐C₂Cl₂F₂ is the best partner molecule for lp···π interaction with the simple molecules, coupled with the greatest interaction energy (IE) and second‐order orbital interaction [E(2) value], whereas C₂F₄ is the poorest one. The C₂Cl₃F·H₂CO and C₂Cl₄·H₂CO complexes exhibit reverse lp···π bonding, while the Z/E‐C₂Cl₂F₂·NH₃, C₂Cl₃F·NH₃ and C₂Cl₄·NH₃ complexes perform half‐lp···π bonding according to the NBO analysis. The lp···π interaction involving the oxygen/nitrogen and the π‐hole of C₂Cl_nF_4?n overwhelms the HaB involving the oxygen/nitrogen and the σ‐hole of the Cl atom. The electron‐donating methyl groups contribute significantly to the two competitive interactions, therefore, DME and TMA engage stronger in the partner molecules than H₂CO and NH₃. Our theoretical study would be useful for future experimental investigation on noncovalent complexes. © 2016 Wiley Periodicals, Inc.     

Chromium-silicon multiple bonds: the chemistry of terminal N-heterocyclic-carbene-stabilized halosilylidyne ligands

An efficient method for the synthesis of the first N‐heterocyclic carbene (NHC)‐stabilized halosilylidyne complexes is reported that starts from SiBr₄. In the first step, SiBr₄ was treated with one equivalent of the N‐heterocyclic carbene 1,3‐bis[2,6‐bis(isopropyl)phenyl]imidazolidin‐2‐ylidene (SIdipp) to give the 4,5‐dihydroimidazolium salt [SiBr₃(SIdipp)]Br ( 1‐Br ), which then was reduced with potassium graphite to afford the silicon(II) dibromide–NHC adduct SiBr₂(SIdipp) ( 2‐Br ) in good yields. Heating 2‐Br with Li[CpCr(CO)₃] afforded the complex [Cp(CO)₂Cr?SiBr(SIdipp)] ( 3‐Br ) upon elimination of CO. Complex 3‐Br features a trigonal‐planar‐coordinated silicon center and a very short Cr?Si double bond. Similarly, the reaction of SiCl₂(SIdipp) ( 2‐Cl ) with Li[CpCr(CO)₃] gave the analogous chloro derivative [Cp(CO)₂Cr?SiCl(SIdipp)] ( 3‐Cl ). Complex 3‐Br undergoes an NHC exchange with 1,3‐dihydro‐4,5‐dimethyl‐1,3‐bis(isopropyl)‐2H‐imidazol‐2‐ylidene (IMe₂iPr₂) to give the complex [Cp(CO)₂CrSiBr(IMe₂iPr₂)₂] ( 4‐Br ). Compound 4‐Br features a distorted‐tetrahedral four‐coordinate silicon center. Bromide abstraction occurs readily from 4‐Br with Li[B(C₆F₅)₄] to give the putative silylidene complex salt [Cp(CO)₂Cr?Si(IMe₂iPr₂)₂][B(C₆F₅)₄], which irreversibly dimerizes by means of an Si‐promoted electrophilic activation of one carbonyl oxygen atom to yield the dinuclear siloxycarbyne complex [Cp(CO)Cr{(μ‐CO)Si(IMe₂iPr₂)₂}₂‐ Cr(CO)Cp][B(C₆F₅)₄]₂ ( 5 ). All compounds were fully characterized, and the molecular structures of 2‐Br – 5‐Br were determined by single‐crystal X‐ray diffraction. DFT calculations of 3‐Br and 3‐Cl and their carbene dissociation products [Cp(CO)₂Cr?Si? X] (X=Cl, Br) were carried out, and the electronic structures of 3‐Br , 3‐Cl and [Cp(CO)₂Cr?Si? X] were analyzed by the natural bond orbital method in combination with natural resonance theory.     

基于1-(2-吡啶甲基)-1,2,4-三唑的金属有机化合物的合成及反应研究(英文)

合成了1-(2-吡啶甲基)-1,2,4-三唑(L)并研究了其与有机锡和羰基钼(钨)的配位反应,合成了通过三唑4位氮原子以单齿形式配位的有机锡衍生物L2SnR2Cl2(R=Me,n-Bu或Ph)和羰基金属配合物LM(CO)5(M=Mo或W),以及N,N螯合双齿配位的四羰基金属配合物LM(CO)4。当用氯化苄处理L时,制得了相应的三唑盐,该盐用氧化银处理后与M(CO)5THF或M(CO)4(NHC5H10)2(NHC5H10为哌啶)反应,得到了基于三唑的氮杂环卡宾衍生物L′M(CO)5和L′M(CO)4(L′=1-(2-吡啶甲基)-4-苄基-1,2,4-三唑-5-碳烯)。X-射线单晶衍射分析表明,在L′M(CO)5中氮杂环卡宾配体L′表现为通过卡宾碳配位的单齿配体;而在L′M(CO)4中,L′表现为通过卡宾碳和吡啶氮原子配位的螯合[C,N]双齿配体。     

On the Reactivity of NHCtBuAuCl towards Rb6Cs6Si17: The First Gold-Silicon Cluster [(NHCtBuAu)6(η2-Si4)]Cl2·7NH3 and an Imide Capped Gold Triangle (NHCtBuAu)3NHCl

Crystals of the two new compounds (NHC^tBuAu)₃NHCl and [(NHC^tBuAu)₆(η²-Si₄)]Cl₂ · 7NH₃ could be isolated from the reaction of Rb₆Cs₆Si₁₇ with NHC^tBuAuCl in the presence of [2.2.2]-cryptand in liquid ammonia. Both compounds were characterized by single-crystal X-ray diffraction and crystallize trigonally without any alkali metals or chelating ligands. Additionally, the crystal of [(NHC^tBuAu)₆(η²-Si₄)]Cl₂ · 7NH₃ was further interpreted by means of ELF and NBO calculations. In the case of (NHC^tBuAu)₃NHCl, NMR experiments provided an exceptional insight into the reaction processes in solution and allowed for the detection of sequential precursors. In the class of capped gold triangles (NHC^tBuAu)₃NHCl impresses with its unique characteristics of being capped by an imide and bound to N-heterocyclic carbenes as ligands instead of the ubiquitously employed phosphines. The gold capped silicon tetrahedron [(NHC^tBuAu)₆(η²-Si₄)]Cl₂ · 7NH₃ represents the first known silicide-gold compound, as well as the first known functionalized Zintl anion, crystallized with a cationic central moiety.     

Heteronukleare Metallatomcluster der Typen X4−n[SnM(CO)4P(C6H5)3]n und M2(CO)8 [μ-Sn(X)M (CO)4P(C6H5)3]2 aus Umsetzungen von SnX2 mit M2(CO)8[P(C6H5)3]2 (X = Halogen; M = Mn,Re; n = 2, 3)

Heteronuclear Metal Atom Clusters of the Types X_4?n[SnM(CO)₄P(C₆H₅)₃]_n and M₂(CO)₈[μ-Sn(X)M(CO)₄P(C₆H₅)₃]₂ by Reaction of SnX₂ with M₂(CO)₈[P(C₆H₅)₃]₂ (X = Halogene; M = Mn, Re; n = 2, 3) The compounds of the both types X_4?n[SnM(CO)₄P(C₆H₅)₃]_n (n = 3; M = Mn; X = F, Cl, Br, I. n = 2: M = Mn, Re; X = Cl, Br, I) and M₂(CO)₈[μ-Sn(X)M(CO)₄P(C₆H₅)₃]₂ (M = Mn; X = Cl, I. M = Re; X = Cl, Br, I) are prepared by reaction of SnX₂ with M₂(CO)₈[P(C₆H₅)₃]₂ (M = Mn, Re). Their IR frequencies are assigned. In Re₂(CO)₈[μ-Sn(Cl)Re(CO)₄P(C₆H₅)₃]₂ the central molecule fragment contains a planar Re₂Sn₂ rhombus with a transannular Re? Re bond of 316.0(2) pm. Each of the Sn^IV atoms is connected with the terminal ligands Cl and Re(CO)₄P(C₆H₅)₃. These ligands are in transposition with respect to the Re₂Sn₂ ring. The mean values for the remaining bond distances (pm) are: Sn? Re = 274.0(3); Sn? Cl = 243(1), Re? C = 176(5), Re? P = 242.4(9), C? O = 123(5). The factors with an influence on the geometrical shape of such M₂Sn₂ rings (M = transition metal) are discussed.     

Double complex salts with [Ru(NH3)5Cl]2+ cation and [OsCl6]2? anion: Synthesis and properties. Crystal structure of [Ru(NH3)5Cl]2[OsCl6]Cl2

Double complex salts [Ru(NH₃)₅Cl][OsCl₆] and [Ru(NH₃)₅Cl]₂[OsCl₆]Cl₂ were prepared and characterized. An X-ray diffraction study showed that [Ru(NH₃)₅Cl][OsCl₆] is isostructural to the previously synthesized [Rh(NH₃)₅Cl][OsCl₆]. The structure of [Ru(NH₃)₅Cl]₂[OsCl₆]Cl₂ was solved by X-ray diffraction (a = 11.1849(8) ?, b = 7.9528(6) ?, c = 13.4122(9) ?; β = 99.765(2)°; V= 1175.75 ?³; space group C2/m; Z = 2). Thermolysis of the compounds under hydrogen and helium was studied. According to X-ray diffraction, nanosized metallic powders of the corresponding alloys are formed as the final products of thermolysis. The compositions of the obtained solid solutions are consistent with the phase diagram of the Ru-Os system.     

The solid state reaction between hexaamminechromium(III) complexes and L-α-alanine

The solid reaction between [Cr(NH₃)₆]X₃(X^? = Cl, I, SCN and NO₃) and L-α-alanine was studied under continuous rise in temperature and isothermal heating. Under continuous rise in temperature, the main products were [Cr(NCS)₃-(NH₃)₃] (X^? = NCS) and [Cr(L-ala)₃] (X^? = NO₃), when [Cr(NH₃)₆]Cl₃ and [Cr(NH₃)₆]I₃ as starting complexes were used; in both cases only the decomposition proceeds. Under isothermal heating at 150°C the main products were [CrCl(NH₃)₅]-Cl₂ (X^? = Cl), [Cr(NH₃)₆]I₂ (X^? = I), [Cr(NCS)₃(NH₃)₃] (X^? = SCN) and [Cr(L-ala)₃] (X^? = NO₃). In those matrix reactions, the ease of anion coordination was: SCN^? > Cl^? > I^? > alanine. For the synthesis of tris(alaninato)chromium(III) complex the most desirable starting complex was [Cr(NH₃)₆](NO₃)₃.The solid state reaction between [Cr(en)₃]X₃ type complexes and NH₄X (X^? = F, Cl, Br, I and SCN), KX (X^? = Cl, Br and I), and NaSCN have been reported by Wendlandt and Stembridge¹. They reported that the reaction product in most cases, was cis-[Cr(en)₂Y₂]X, where Y and X are the same or different anions, depending upon the matrix material employed and the thermal matrix method appears to be a useful new route for the synthesis of bis(ethylendiamine(chromium(III) complexes.In the previous paper², the solid state reaction between [Cr(NH₃)₆](NO₃)₃ and L-amino acids has been utilized in the preparation of tris(amino acidato)chromium(III) complexes. The preparation of [Cr(L-ala)₃] by the solid state reaction between [Cr(NH₃)₆](NO₃)₃ and L-alanine have been reported. No studies on the effect of the counter-ion have been reported.In this paper, various hexaamminechromium(III) complexes, [Cr(NH₃)₆]X₃ (X^? = Cl, I, SCN and NO₃), were heated with L-α-alanine under continuous rise in temperature and under isothermal heating at 150°C for studies on the ease of anion coordination. It will seen that the anion which replaces the ammonia in the hexaamminechromium(III) complex comes from either the alanine or counter-ion.     

Aryl- and acetylene-nickel(I) complexes

Reduction of various pentafluorophenylnickel(II) complexes in the presence of phosphines gives unstable nickel(I) compounds but Ni(C₆F₅)(CO)₂(PPh₃)₂ is isolated in the presence of CO. Similar NiR(CO)₂(PPh₃)₂ (R = C₆F₅,C₆Cl₅, 2,3,5,6-C₆Cl₄H) are obtained by reaction of the halogenonickel(I) complex with MgRBr or LiR. Reduction of NiX₂L₂ in the presence of acetylenes gives [NiXL₂]₂(μ-PhCCR) (R = H, X = Cl and R = Ph, X = Cl, Br) when L = P-n-Bu₃ but only NiX(PPh₃)₃ are recovered when L = PPh₃. No reaction with the alkyne is observed for [NiX(PPh₃)₂]_n but [NiCl(PPh₃)]_n reacts with RCCR′ to give paramagnetic NiCl(PPh₃)(CRCR′) (R = Ph, R′= H, COOEt), diamagnetic [NiCl(PPh₃)]₂(μ-PhCCPh) and cyclotrimerization when R = R′ = COOMe. Chemical and structural behaviour of the new nickel(I) complexes is described.