Ag[Fe(CO)5]2+: A Bare Silver Complex with Fe(CO)5 as a Ligand

Attempts to prepare Fe(CO)₅⁺ from Ag[Al(OR^F)₄] (R^F=C(CF₃)₃) and Fe(CO)₅ in CH₂Cl₂ yielded the first complex of a neutral metal carbonyl bound to a simple metal cation. The Ag[Fe(CO)₅]₂⁺ cation consists of two Fe(CO)₅ molecules coordinating Ag⁺ in an almost linear fashion. The ν(CO) modes are blue‐shifted compared to Fe(CO)₅, with one band above 2143 cm^?1 indicating that back‐bonding is heavily decreased in the Ag[Fe(CO)₅]₂⁺ cation.     

Mapping the Transformation [{RuII(CO)3Cl2}2]→[RuI2(CO)4]2+: Implications in Binuclear Water–Gas Shift Chemistry

The complete sequence of reactions in the base‐promoted reduction of [{Ru^II(CO)₃Cl₂}₂] to [Ru^I₂(CO)₄]²⁺ has been unraveled. Several μ‐OH, μ:κ²‐CO₂H‐bridged diruthenium(II) complexes have been synthesized; they are the direct results of the nucleophilic activation of metal‐coordinated carbonyls by hydroxides. The isolated compounds are [Ru₂(CO)₄(μ:κ²‐C,O‐CO₂H)₂(μ‐OH)(NP^F‐Am)₂][PF₆] ( 1 ; NP^F‐Am=2‐amino‐5,7‐trifluoromethyl‐1,8‐naphthyridine) and [Ru₂(CO)₄(μ:κ²‐C,O‐CO₂H)(μ‐OH)(NP‐Me₂)₂][BF₄]₂ ( 2 ), secured by the applications of naphthyridine derivatives. In the absence of any capping ligand, a tetranuclear complex [Ru₄(CO)₈(H₂O)₂(μ³‐OH)₂(μ:κ²‐C,O‐CO₂H)₄][CF₃SO₃]₂ ( 3 ) is isolated. The bridging hydroxido ligand in 1 is readily replaced by a π‐donor chlorido ligand, which results in [Ru₂(CO)₄(μ:κ²‐C,O‐CO₂H)₂(μ‐Cl)(NP‐PhOMe)₂][BF₄] ( 4 ). The production of [Ru₂(CO)₄]²⁺ has been attributed to the thermally induced decarboxylation of a bis(hydroxycarbonyl)–diruthenium(II) complex to a dihydrido–diruthenium(II) species, followed by dinuclear reductive elimination of molecular hydrogen with the concomitant formation of the Ru^I? Ru^I single bond. This work was originally instituted to find a reliable synthetic protocol for the [Ru₂(CO)₄(CH₃CN)₆]²⁺ precursor. It is herein prescribed that at least four equivalents of base, complete removal of chlorido ligands by Tl^I salts, and heating at reflux in acetonitrile for a period of four hours are the conditions for the optimal conversion. Premature quenching of the reaction resulted in the isolation of a trinuclear Ru^I₂Ru^II complex [{Ru(NP‐Am)₂(CO)}{Ru₂(NP‐Am)₂(CO)₂(μ‐CO)₂}(μ₃:κ³‐C,O,O′‐CO₂)][BF₄]₂ ( 6 ). These unprecedented diruthenium compounds are the dinuclear congeners of the water–gas shift (WGS) intermediates. The possibility of a dinuclear pathway eliminates the inherent contradiction of pH demands in the WGS catalytic cycle in an alkaline medium. A cooperative binuclear elimination could be a viable route for hydrogen production in WGS chemistry.     

Salts of the cobalt(I) complexes [Co(CO)5]+ and [Co(CO)2(NO)(2)]+ and the Lewis acid-base adduct [Co2(CO)7CO--B(CF3)3

The reaction of [Co(2)(CO)(8)] with (CF(3))(3)BCO in hexane leads to the Lewis acid-base adduct [Co(2)(CO)(7)CO--B(CF(3))(3)] in high yield. When the reaction is performed in anhydrous HF solution [Co(CO)(5)][(CF(3))(3)BF] is isolated. The product contains the first example of a homoleptic metal pentacarbonyl cation with 18 valence electrons and a trigonal-bipyramidal structure. Treatment of [Co(2)(CO)(8)] or [Co(CO)(3)NO] with NO(+) salts of weakly coordinating anions results in mixed crystals containing the [Co(CO)(5)](+)/[Co(CO)(2)(NO)(2)](+) ions or pure novel [Co(CO)(2)(NO)(2)](+) salts, respectively. This is a promising route to other new metal carbonyl nitrosyl cations or even homoleptic metal nitrosyl cations. All compounds were characterized by vibrational spectroscopy and by single-crystal X-ray diffraction.     

Synthese von Kupfer- und Silberkomplexen mit fünfzähnigen N,S- und sechszähnigen N,O-Chelatliganden – Charakterisierung und Kristallstrukturen von {Cu2[C6H4(SO2)NC(O)]2(C5H5N)4}, {Cu2[C5H3N(CHNC6H4SCH3)2]2}(PF6)2 und {Ag[C5H3N(CHNC6H4SCH3)2]}PO2F2

Synthesis of Copper and Silver Complexes with Pentadentate N,S and Hexadentate N,O Chelate Ligands – Characterization and Crystal Structures of {Cu₂[C₆H₄(SO₂)NC(O)]₂(C₅H₅N)₄}, {Cu₂[C₅H₃N(CHNC₆H₄SCH₃)₂]₂}(PF₆)₂, and {Ag[C₅H₃N(CHNC₆H₄SCH₃)₂]}PO₂F₂ In the course of the reaction of copper(II)-acetate monohydrate with 2,2′-bisbenzo[d][1,3]thiazolidyl in methanol the organic component is transformed to N,N′-bis-(2-thiophenyl)ethanediimine and subsequently oxidized to the N,N′-bis-(2-benzenesulfonyl)ethanediaciddiamide H₄BBSED, which coordinates in its deprotonated form two Cu²⁺ ions. Crystallisation from pyridine/n-hexane yields [Cu₂(BBSED)(py)₄] · MeOH. It forms triclinic crystals with the space group P1 and a = 995.5(2) pm, b = 1076.1(3) pm, c = 1120.7(2) pm, α = 104.17(1)°, β = 105.28(1)°, γ = 113.10(1)° and Z = 1. In the centrosymmetrical dinuclear complex the copper ions are coordinated in a square-pyramidal arrangement by three nitrogen and two oxygen atoms. The Jahn-Teller effect causes an elongation of the axial bond by approximately 30 pm. The reactions of the pentadentate ligand 2,6-Bis-[(2- methylthiophenyl)-2-azaethenyl]pyridine BMTEP with salts of copper(I), copper(II) and silver(I) yield the complexes [CU₂(BMTEP)₂](PF₆)₂, [Cu(BMTEP)]X₂ (X = BF, C1O) and [Ag(BMTEP)]X (X = PO₂F, ClO). [Cu₂(BMTEP)₂](PF₆)₂ crystallizes from acetone/diisopropyl- ether in form of monoclinic crystals with the space group C2/c, and a = 1833.2(3) pm, b = 2267.30(14) pm, c = 1323.5(2) pm, β= 118.286(5)°, and 2 = 4. In the dinuclear complex cation with the symmetry C₂ the copper ions are tetrahedrally coordinated by two bridging BMTEP ligands. The Cu? Cu distance of 278.3pm can be interpreted with weak Cu? Cu interactions which also manifest itself in a temperature independent paramagnetism of 0.45 B.M. The monomeric silver complex [Ag(BMTEP)]PO₂F₂ crystallizes from acetone/thf in the triclinic space group P1 with a = 768.7(3) pm, b = 1074.0(5) pm, c = 1356.8(5) pm, α = 99.52(2)°, β = 96.83(2)°, γ = 99.83(2)° and Z = 2. The central silver ion is coordinated by one sulfur and three nitrogen atoms of the ligand in a planar, semicircular arrangement. The bond lengths Ag? N = 240.4–261.7 and Ag? S = 257.2 pm are significantly elongated in comparison with single bonds.     

Alkaline Earth Diazapentadienyl Compounds: Structure of [Ba2{(C6H11)NC(Me)CHC(Me)N(C6H11)}3{(SiMe3)2N}]

Three different bonding modes in one molecule! The diazapentadienyl ligands in the title compound 1 adopt η¹,η¹-N,N-chelating plus η⁵-terminal, η¹η¹-N,N chelating plus η⁵-bridging, and novel η¹-N plus η³-1-aza-allyl bonding modes. R=cyclohexyl.     

Copper halide-bridged ruthenium telluride carbonyl complexes: discovery of the semiconducting cluster chain polymer {[PPh4]2[Te2Ru4(CO)10Cu4Br2Cl2].THF}infinity

A new series of Te-Ru-Cu carbonyl complexes was prepared by the reaction of K(2)TeO(3) with [Ru(3)(CO)(12)] in MeOH followed by treatment with PPh(4)X (X=Br, Cl) and [Cu(MeCN)(4)]BF(4) or CuX (X=Br, Cl) in MeCN. When the reaction mixture of K(2)TeO(3) and [Ru(3)(CO)(12)] was first treated with PPh(4)X followed by the addition of [Cu(MeCN)(4)]BF(4), doubly CuX-bridged Te(2)Ru(4)-based octahedral clusters [PPh(4)](2)[Te(2)Ru(4)(CO)(10)Cu(2)X(2)] (X=Br, [PPh(4)](2)[1]; X=Cl, [PPh(4)](2)[2]) were obtained. When the reaction mixture of K(2)TeO(3) and [Ru(3)(CO)(12)] was treated with PPh(4)X (X=Br, Cl) followed by the addition of CuX (X=Br, Cl), three different types of CuX-bridged Te-Ru carbonyl clusters were obtained. While the addition of PPh(4)Br or PPh(4)Cl followed by CuBr produced the doubly CuBr-bridged cluster 1, the addition of PPh(4)Cl followed by CuCl led to the formation of the Cu(4)Cl(2)-bridged bis-TeRu(5)-based octahedral cluster compound [PPh(4)](2)[{TeRu(5)(CO)(14)}(2)Cu(4)Cl(2)] ([PPh(4)](2)[3]). On the other hand, when the reaction mixture of K(2)TeO(3) and [Ru(3)(CO)(12)] was treated with PPh(4)Br followed by the addition of CuCl, the Cu(Br)CuCl-bridged Te(2)Ru(4)-based octahedral cluster chain polymer {[PPh(4)](2)(Te(2)Ru(4)(CO)(10)Cu(4)Br(2)Cl(2)).THF}(infinity) ({[PPh(4)](2)[4].THF}(infinity)) was produced. The chain polymer {[PPh(4)](2)[4].THF}(infinity) is the first ternary Te-Ru-Cu cluster and shows semiconducting behavior with a small energy gap of about 0.37 eV. It can be rationalized as resulting from aggregation of doubly CuX-bridged clusters 1 and 2 with two equivalents of CuCl or CuBr, respectively. The nature of clusters 1-4 and the formation and semiconducting properties of the polymer of 4 were further examined by molecular orbital calculations at the B3LYP level of density functional theory.     

Coordination chemistry of the soluble metal oxide analogue [Mo5O13(OCH3)4(NO)]3- with manganese carbonyl species

The reactions of neutral or cationic manganese carbonyl species towards the oxo-nitrosyl complex [Na(MeOH)[Mo(5)O(13)(OCH(3))(4)(NO)]](2-) have been investigated in various conditions. This system provides an unique opportunity for probing the basic reactions involved in the preparation of solid oxide-supported heterogeneous catalysts, that is, mobility of transition-metal species at the surface and dissolution-precipitation of the support. Under nitrogen and in the dark, the reaction of in situ generated fac-[Mn(CO)(3)](+) species with (nBu(4)N)(2)[Na(MeOH)-[Mo(5)O(13)(OMe)(4)(NO)]] in MeOH yields (nBu(4)N)(2)[Mn(CO)(3)(H(2)O)[Mo(5)O(13)(OMe)(4)(NO)]] at room temperature, while (nBu(4)N)(3)[Na[Mo(5)O(13)(OMe)(4)(NO)](2)[Mn(CO)(3)](2)] is obtained under reflux. The former transforms into the latter under reflux in methanol in the presence of sodium bromide; this involves the migration of the fac-[Mn(CO)(3)](+) moiety from a basal kappa(2)O coordination site to a lateral kappa(3)O site. Oxidation and decarbonylation of manganese carbonyl species as well as degradation of the oxonitrosyl starting material and reaggregation of oxo(methoxo)molybdenum fragments occur in non-deareated MeOH, and both (nBu(4)N)(4)[Mn(H(2)O)(2)[Mo(5)O(16)(OMe)(2)](2)[Mn(CO)(3)](2)] and (nBu(4)N)(4)[Mn(H(2)O)(2)[Mo(5)O(13)(OMe)(4)(NO)](2)] as well as (nBu(4)N)(2)[MnBr[Mo(5)O(13)(OMe)(4)(NO)]] have been obtained in this way. The rhenium analogue (nBu(4)N)(2)[Re(CO)(3)(H(2)O)[Mo(5)O(13)(OMe)(4)(NO)]] has also been synthesized. The crystal structures of (nBu(4)N)(2)[Re(CO)(3)(H(2)O)[Mo(5)O(13)(OMe)(4)(NO)]], (nBu(4)N)(3)[Na[Mo(5)O(13)(OMe)(4)(NO)](2)[Mn(CO)(3)](2)], (nBu(4)N)(4)[Mn(H(2)O)(2)[Mo(5)O(16)(OMe)(2)](2)[Mn(CO)(3)](2)], (nBu(4)N)(4)[Mn(H(2)O)(2)[Mo(5)O(13)(OMe)(4)(NO)](2)] and (nBu(4)N)(2)[MnBr[Mo(5)O(13)(OMe)(4)(NO)]] have been determined.     

Umsetzung von C(NMe2)4 mit Ni(CO)4 – Synthesen und Strukturen von [C(NMe2)3][(CO)3NiC(O)NMe2], [C(NMe2)3]2[Ni5(CO)12] und [C(NMe2)3]3[Ni6(CO)12][O2CNMe2]

Reaction of C(NMe₂)₄ with Ni(CO)₄ – Syntheses and Structures of [C(NMe₂)₃][(CO)₃NiC(O)NMe₂], [C(NMe₂)₃]₂[Ni₅(CO)₁₂], and [C(NMe₂)₃]₃[Ni₆(CO)₁₂][O₂CNMe₂] The reaction of C(NMe₂)₄ with Ni(CO)₄ in THF produces the carbamoyl complex [C(NMe₂)₃][(CO)₃NiC(O)NMe₂] ( 1 ); side products are the purple cluster compound [C(NMe₂)₃]₂[Ni₅(CO)₁₂] · THF ( 2 · THF) and the red cocristallization product [C(NMe₂)₃]₃[Ni₆(CO)₁₂][O₂CNMe₂] ( 3 ). All compounds were studied by X‐ray diffraction analyses. The cations of 3 are all disordered but not those of 1 and 2 . The unit cell of 1 contains two crystallographically independent anions (I and II) which differ in the dihedral angle between the plane of the carbamoyl ligand and the plane defined by the atoms C_Carbamoyl–Ni–CO amounting 0° in the anion I and 18° in the anion II.     

Bildung und Struktur des [{cyclo‐P4(PtBu2)4}{Ni(CO)2}2]

Coordination Chemistry of P‐rich Phosphanes and Silylphosphanes. XXVI. Formation and Structure of [{ cyclo ‐P₄(P^tBu₂)₄}{Ni(CO)₂}₂] [{cyclo‐P₄(P^tBu₂)₄}{Ni(CO)₂}₂] is formed by reaction of the cyclotetraphosphane P₄(P^tBu₂)₄ with [Ni(CO)₄]. Each Ni(CO)₂ unit is coordinated by two adjacent ^tBu₂P groups forming two five‐membered P₄Ni rings above and below the planar cyclotetraphosphane ring, respectively. The compound crystallizes in the triclinic space group P 1 (No. 2) with a = 893.29(5), b = 1140.75(7), c = 1235.52(8) pm, α = 109.179(7), β = 100.066(7), γ = 97.595(7)° and Z = 1.