Electrical conductivity of liquid and film polymer composites filled with anion-radical salts in the presence of crown ethers

In the example of alkali metal tetracyanoquinodimethanides (M⁺TCQDM), a study has been made of the influence of resonance charge exchange on the conductivity () of polymer composites filled with anion-radical salts. When neutral molecules TCQDM⁰ are introduced into such systems, this leads to an increase in as a result of the lower activation energy of jumps between states TCQDM and TCQDM⁰. The addition of molecules of crown ethers has an analogous effect: They favor the appearance in the polymer matrix (the same as in solution) of TCQDM molecules in different charge states (TCQDM⁰, TCQDM) with migration of the cation within the limits of ternary associates (CE...M⁺...A) that are formed in systems for which the ratio of the crown ether cavity diameter to the cation diameter 1.4. Symbaticity has been found in the dependences of the electrical conductivity of films and the limiting mobility of solutions with the same composition on the parameter .Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 4, pp. 446–452, July–August, 1989.     

Crystal structure of a dimeric nickel(II) complex with 3-imidazoline nitroxide radical

The crystal structure of an unusual dimeric Ni(II) complex with 3-imidazoline nitroxide LH=C₉H₁₄N₂O₂ of the formula Ni₂(LH)₄ has been determined. The structure is molecular, space group P2₁/c, with a=12.150(3) Å, b=11.229(3) Å, c=15.780(4) Å, =101.59(3)^o, and d _calc =1.54 g/cm³, for Z=2; V=2109(1) ų, R=0.059. In the centrosymmetric dimer, the Ni...Ni distance is 3.254(2) Å; the coordination polyhedron of Ni is a square pyramid (the coordination number is 5) formed by the donor O and N atoms of LH ligands acting as the bidentate-cyclic and bidentate bridged-cyclic structures. The Ni–O and Ni–N distances are 1.989(7) and 2.032(8) Å, respectively (for the atoms forming the pyramid base), and 2.000(8) Å to the apical N atom. The Ni atom is displaced from the base to the apex of the pyramid by 0.35 Å. The interatomic distances and the bond angles in the ligands agree with those for the previously studied M(LR)₂ complexes. The distances between the Ni(II) ions and the O O atoms inside the Ni(LH)₂ fragments are 5.39(1) and 5.45(1) Å, the intermolecular Ni...O distances exceed 6 Å, and the O...O distances are as long as 4.73(1) Å.Institute of Inorgamic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Stukturnoi Khimii, Vol. 34, No. 3, pp. 80–85, May–June 1993.Translated by T. Yudanova     

Substituted metal carbonyls. Part 25: Unidentate,intramolecular, and intermolecular bridging modes of 1,1′-bis(diphenylphosphino)ferrocene inM 3S2(CO)9 (M = Fe,Ru) cluster derivatives

Carbonyl exchange of Fe₃(₃-S)₂(CO)₉ wioth1,1-bis(diphenylphosphino)ferrocene (dppf) in refluxing THF gives a cluster ligand with a pendant phosphine moiety, Fe₃(₃-S)₂(CO)₈ (gn¹-Ph₂PlC₅H₄)Fe(C₅H₄)P⁴ MePh₂)]1 ^–,4. Addition of 1 to AuCl(SMe₂) gives ClAu(-dppf) Fe₄(₃-S)₂(CO)₈,8 (45%). Spectroscopic evidence is also obtained for (OC)₈ (₃-S)₂Fe₃(-dppf) Os₃(CO)₁₁,7 and PdCl₂[(-dppf)Fe₃(₃-D)₂(CO)₈]₂,9, from1 and Os₃(CO)₁₁(CH₃CN) and PdCl₂CN)₂, respectively. Crystal data dor3: space group P2₁/n,a = 10.891(3) Å,b = 19.939(3) Å,c = 20.443(2) Å, 100.17(2)°.Z = 4, 3917 reflections,R = 0.049.     

Triiron and Triruthenium Carbonyl Clusters Bearing Bridging Long Chain Diphosphine and Capping Chalcogenido Ligands

Treatment of Ru₃(CO)₁₂ with dpphSe₂ (dpph = 1,6-bis(diphenylphosphino)hexane) in refluxing toluene in the presence of Me₃NO afforded two new compounds, Ru₃(CO)₇(-CO)(₃-Se)(-dpph) (1) and Ru₃(CO)₇(₃-Se)₂(-dpph) (2). A similar reaction of Ru₃(CO)₁₂ with dpppeSe₂ (dpppe = 1,5-bis(diphenylphosphino)pentane) gave exclusively Ru₃(CO)₇(₃-Se)₂(-dpppe) (3). Treatment of Ru₃(CO)₁₂ with dpphS₂ and dpppeS₂ at 110°C in the presence of Me₃NO afforded Ru₃(CO)₇(₃-S)₂(-dpph) (4) and Ru₃(CO)₇(₃-S)₂(-dpppe) (5), respectively. Reactions of Fe₃(CO)₁₂ with dpphSe₂ and dpppeSe₂, under identical conditions, afforded Fe₃(CO)₇(₃-Se)₂(-dpph) (6) and Fe₃(CO)₇(₃-Se)₂(-dpppe) (7), respectively. Compounds 1–7 were characterized spectroscopically and the molecular structures of compounds 1–4 were determined by single crystal X-ray crystallography. The core of 1 contains an equilateral triangle of ruthenium atoms with one capping selenium, one bridging dpph, one doubly bridging carbonyl and seven terminal carbonyl ligands. Complexes 2–4 have a square-pyramidal structure with two metal and two chalcogenide atoms alternating in the basal plane and the third metal atom at the apex of the pyramid, and belong to the family of well-known nido clusters with seven skeletal electron pairs.     

Di- and tri-nuclear osmium carbonyl chloride complexes: x-ray structures of Os2(CO)8Cl2 and Os3(CO)12Cl2

Summary Os₂(CO)₈Cl₂ (1) is orthorhombic P2₁2₁2₁ witha=9.3599(9),b=9.879(2),c=16.014(3), V=1480³, D_c=3.03 Mgm^–3 for Z=4. Structure solved by Patterson methods. Final R=0.038, R_w=0.038 [w=(²F)] for 1270 observed reflections and 141 parameters. Os₃(CO)₁₂Cl₂ (2) is monoclinic C2/m witha=12.105(3), b=10.612(3),c=8.798(1) , =117.02(2)°, V=1006³, D_c=3.22 Mgm^–3 for Z=2. Structure solved by Patterson methods. Final R=0.036, R_w=0.037 (w=(²F)^–) for 821 observed reflections and 75 parameters.Complex(1) has an osmium-osmium single bond 2.897(1), with the chloride ligands in equatorial positions,(2) has a linear triosmium chain with osmium-osmium single bonds 2.893(1) and the chloride ligands occupy equatorial sites on the terminal osmium atoms. Both(1) and(2) are isostructural with their osmium carbonyl iodide analogues.     

Chemistry on the rhomboidal Ru4 faces of the clusters RU4(CO)13(μ-PR2)2: Novel small molecule,ligand, and skeletal transformations

Tetrametal clusters such as Ru₄(CO)₁₃(-PPh₂)₂ and Ru₄(CO)₁₀(-PPh₂)₄ are 64-electron systems and, with five metal-metal interactions, are formally electron rich. In fact these clusters have unusual rhomboidal (or flat butterfly) structures with three or four elongated Ru-Ru bonds. With molecular orbitals antibonding with respect to metal metal interactions occupied in such clusters, facile two electron oxidation or ligand dissociation processes should occur, giving electron precise molecules. The molecule Ru₄(CO)₁₃(-PPh₂)₂ 1a undergoes a remarkable, reversible transformation upon loss of CO affording (-H)Ru₄(CO)₁₀(-PPh₂)[₄-¹(P),¹(P),¹(P),¹,²-{C₆H₄}PPh]3 a cluster which contains a five coordinate phosphido bridge and an orthometallated ² arene ring. This conversion is reversible under CO. These and other results which will be discussed confirm that M₄ clusters with electrons in excess of the expected EAN rule count may exhibit unusual reactivity. The solid-state CP/MAS and static powder³¹P NMR spectra of some of these clusters exhibit^99/101Ru-³¹P couplings, values of which have been measured for the first time.     

The synthesis and structure of the [2.2]paracyclophane cluster Ru6C(CO)13(μ 3-η 2:η 2:η 2-C16H16)(PPh3) and a study of the 1H-n.m.r. spectra of [2.2]paracyclophane and benzene clusters

Summary The [2.2]paracyclophane cluster, Ru₆C(CO)₁₄( ₃- ^{2 2 2}-C₁₆H₁₆) (1), undergoes reaction with Me₃NO and triphenylphosphine to yield Ru₆C(CO)₁₃( ₃- ^{2 2 2}-C₁₆H₁₆)(PPh₃) (2), which may also be produced from (1) by thermolysis with PPh₃ in THF. Compound (2) has been fully characterized in solution by spectroscopy and in the solid state by a single crystal X-ray diffraction analysis at 277 K, and its structure is compared with that of the parent cluster, (1). Using the same synthetic procedures, the tricyclohexylphosphine analogue, Ru₆C(CO)₁₃( ₃- ^{2 2 2}-C₁₆H₁₆)(PCy₃) (3), has also been prepared and characterized spectroscopically. A comparison of the chemical shifts of the 577-01 protons in the ¹H-n.m.r. spectra of compounds (1)–(3) together with a variety of other [2.2]paracyclophane and benzene clusters has been made.     

Organometallic chemistry and homogeneous catalysis of Rh and Rh-Co mixed metal carbonyl clusters

The reactions of hydrosilane and/or alkyne as well as isonitriles with rhodium and rhodium cobalt mixed metal carbonyl clusters, e.g., Rh₄(CO)₁₂ and Co₂Rh₂(CO)₁₂, are studied. Novel mixed metal complexes, e.g., CoRh(CO)₅ (HCCBu ⁿ ), (R₃Si)₂Rh(CO) _n Co(CO)₄, Rh(R–NC)₄Co(CO)₄, Co₂Rh₂(CO)₁₀(HCCR), and Co₂Rh₂(CO)₉(HCCBu ⁿ ), are synthesized and identified. The catalytic activities of these rhodium and rhodium-cobalt mixed metal complexes are examined in hydrosilyation, silylformylation, and novel silylcarbocyclization reactions. Possible mechanisms for these reactions are proposed and discussed.     

Synthesis and protonation of an OS3(μ-H)(CO)10(μ-σ,η2-C≡CCMe2OMe) cluster

Triosmium cluster Os₃(-H)(CO)₁₀(--²-CCC Me₂OMe) (1) was obtained by treating OS₃(-H)(-Cl)(CO)₁₀ with LiCCCMe₂OMe. The reaction of cluster1 with HBF₄ · Et₂O at –60 °C leads to the cationic complex [Os₃(-H)(CO)₁₀(-,,²-C=C=C Me₂)]⁺BF₄ ^– (2) with an allenylidene ligand. The^s1H and¹³C NMR spectra of complex2 reveal the temperature dependence caused by migration of hydrocarbon and carbonyl ligands. Thermodynamic parameters were obtained for be exchange process of the allenylidene ligand.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp, 2990–2992, December, 1996.     

Synthesis, Characterization and Luminescence Studies of Trinuclear Rhenium–Cobalt Mixed-Metal Alkynyl Complexes Containing a Tetrahedral Co2C2 Cluster Unit

The reaction of rhenium(I) diynyl complexes [Re(CO)₃(N–N)(CC--CCH)] [N–N = ^tBu₂bpy (1), bpy (2)] with Co₂(CO)₈ in THF yielded a new class of luminescent trinuclear rhenium–cobalt mixed-metal alkynyl complexes, [Co₂{-HC₂CC[Re(CO)₃(N–N)]}(CO)₆] [N–N = ^tBu₂bpy (3), bpy (4)]. Their luminescence and electrochemical properties have also been studied.     

Kinetics and mechanisms of halide ion catalysis of CO substitution reactions in Os3(CO)12 and Ru3(CO)12 metal carbonyl clusters

The results of kinetic studies on ligand substitution in [M₃(CO)₁₁X]^– complexes (M = Ru, Os; X = Cl, Br, I) are summarized. The [Os₃(CO)₁₁X]^– complexes react with PPh₃ under mild conditions to initially yield monosubstituted products [Os₃(CO)₁₀(PPh₃)X]^–. The rate of CO substitution obeys a first-order equation with respect to the concentration of the complex and does not depend on the ligand concentration. The rates of the reactions decrease in the order Cl > Br > I withH values increasing from 15 to 18 kcal mol^–1 and S values varying from –19 to –13 cal mol^–1 K^–1. The enhanced reactivities of these complexes as well as the low activation energies and negative activation entropies are discussed in terms of the effects of -X bridge formation on the transition state of the reaction. Reactions of PPN[Ru₃(CO)_11–x (Cl)] (PPN is the bis(triphenylphosphine)iminium cation;x=0, 1) and PPN[Ru₃(CO)₉(₃-I)] with alkynes are also reported. The reactivities of alkynes follow the order BuCCH PhCCH EtCCEt PhCCPh. The higher rates of the reactions of monosubstituted acetylenes compared with those of their disubstituted analogs are explained by agostic interaction between the metal atom and the C-H bond in the reaction transition state and by steric effects. The results obtained attest that the reaction with alkynes occursvia intermediates containing halide bridges and that ₃-halide complexes are more reactive than ₂-halide complexes.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1540–1545, September, 1994.This work was supported by a Presidential Grant from Northwestern University. One of the authors (F. Basolo) wishes to thank Academician M. E. Vol'pin for the invitation to participate in the Workshop The Modern Problems of Organometallic Chemistry (INEOS-94) and Academician O. M. Nefedov for the invitation to publish a review in theRussian Chemical Bulletin.     

Protonation of Os3(μ-H)(CO)9(μ3-σ,η2-C≡C-R) clusters (R=CMe2OH,C(Me)=CH2)

Protonation of triosmium clusters Os₃(-H)(CO)₉(₃-,²-CC-R) (R=CMe₂OH, C(Me)=CH₂) affords a cationic complex containing a six-electron propargyl ligand which has been detected for the first time.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1144–1145, June, 1993.     

Diacetylenic Derivatives of Fe2(CO)6(μ-EE′): Spectroscopic Investigations of Fe2(CO)6{μ-EC(H) = C(C≡ CMe)E′} (E = E′, E ≠ E′; E, E′ = S, Se, Te)

The diacetylenic adducts, Fe₂(CO)₆{-EC(H) = C(C CMe)E} (E = E, E E; E, E = S, Se, Te) (1–8) have been obtained from the room temperature stirring of Fe₂(CO)₆(-EE) with HC CC CMe in methanol solvent containing sodium acetate. Compounds 1–8 have been characterized by IR and multinuclear NMR (¹H, ¹³C, ⁷⁷Se, and ^l25Te) spectroscopy. Trends in the chemical shifts of ⁷⁷Se and ¹²⁵Te NMR spectra of Fe₂(CO)₆{-EC(H) = C(C CMe)E} with a variation of EE are discussed.     

Redox Properties of Trinuclear Osmium Carbonylhydride Clusters with Unsaturated Ligands

Schemes of redox transformations were proposed for osmium carbonylhydride clusters: trinuclear (-H)Os₃(-CR = CHR')(CO)_{1 0} (R = R' = H, Ph; R = H, R' = Ph), (-H)₂Os₃(₃-L)(CO)₉ (L = C = CHPh, CHCPh), tetranuclear CpMnOs₃ (-CH = CHPh)(-H)(-CO)(CO)_{1 1}, and trinuclear Os₃(₃-C = CHPh)(CO)₉. Two-electron reduction of the trinuclear clusters results in elimination of the unsaturated ligand with preservation of the metal framework.     

Coupling insertion reactions of diphenylbuta-1, 4-diyne into iron-carbene bonds of [Fe2(CO)7{μ-C(Ph)C(NEt2}]. Syntheses and reactivities of the ferracyclopentadiene [Fe2(CO)6{C(Ph)C(NEt2)C(Ph)C(C2Ph)}] with [Fe2(CO)9]

The diiron ynamine complex [Fe₂(CO)₇{-C(Ph)C(NEt₂)}] (1) reacts with the diphenylbuta-1, 4-diyne, PhCC-CCPh, in refluxing hexane to yield three isomer complexes [Fe₂(CO)₆{C(Ph)C(NEt₂)C(Ph)C(C₂Ph}] (2a), [Fe₂(CO)₆{C(Ph)C(NEt₂)C(C₂Ph)C(Ph)}] (2b), and [Fe₂(CO)₆{NEt₂)C(Ph)C(C₂)C(Ph)}] (2c) All three compounds were identified by their¹H NMR spectra. Compounds2a and2c were characterized by single crystal X-ray diffraction analyses. Crystal data: for2a: space group = P2₁/n,a = 17.873(1) Å, = 18.388(6) Å,c = 9.429(3) Å = 91.99(3)°,Z = 4.3751 reflections,R = 0.044; for2c: space group = P2₁/n,a = 40.58(2) å,b = 12.101(9) Å,c = 12.551(5) Å, = 94.29(7)°,Z = 8.4723 reflection,R = 0.076. Complexes2a and2b result from a [2 + 2] cycloaddition between one of the CC triple bonds of the diyne ligand and the FeC carbene bond, whereas2c results from insertion of one of the CC group into the bridging carbene. Addition of [Fe₂(CO)₉] on2a gave two major products, the tripledecker [Fe₃(CO)₈{C(Ph)C(NEt₂)C(C₂Ph)}], (3 and a tetrairon cluster [Fe₄(CO)₁₁{C(Ph)C(NEt₂)C(Ph)C(C₂Ph)}] (4). Both compounds were characterized by single crystal diffraction analyses. Crystal data: for3: space group = P2₁/n,a = 12.039(3) Å,b = 18.046(3) å,c = 15.270(2) Å, = 90.11(2)°,Z = 4, 1430 reflections,R = 0.067; for4 space group = C2/c,a = 18.633(3) Å,b = 21.467(1)_Å,c = 20.742(2) Å, = 115.03(8)°,Z = 8.992 reflections, R = 0.076. Complex4 is based on a spiked triangular cluster with the alkynyl triple bond attached in ₃-parallel mode on the triangular grouping.     

Migration of the η1:η6-C6H5Cr(CO)3 ligand into the cyclopentadienyl ring during metallation of the η5-C5H5(CO)2Fe η1:η6-C6H5Cr(CO)3 binuclear complex

It was found that the ¹⁶-C₆H₅Cr(CO)₃ ligand migrates into the cyclopentadienyl ring when the ⁵-C₅H₅(CO)₂Fe ¹⁶-C₆H₅Cr(CO)₃ binuclear complex is metallated with BuⁿLi. Under the same conditions, no migration of the phenyl ligand in the ⁵-C₅H₅(CO)₂Fe ¹-C₆H₅ complex was observed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 325–326, February, 1994.     

The reaction of [PPN][(μ2-H)Os3(CO)10(μ2-CO)] with EPh3 (E=P or As) to form the intermediate [PPN][Os3(CO)9(ν2-CHO)(EPh3)]

The anion, [(₂-H)Os₃(CO)₁₀(₂-CO)]^–, reacts with the donor ligand EPh₃ (E=P or As) to produce, as an intermediate in the reaction to the substituted anion [(₂-H)Os₃(CO)₉(₂-CO)(EPh₃)]^–, a moderately stable formyl derivative which we tentatively formulate as [Os₃(CO)₉(²-CHO)(EPh₃)]^–.     

Second Molecular Hyperpolarizability of Mixed Transition Metal, Non-Metal Clusters

The real and imaginary parts of third order nonlinear optical susceptibilities ( ⁽³⁾) of 10^–4M solutions of [{Fe₂(CO)₆}( ₃-Y₃P){CpCr(CO)₂}] (Y=S (1) or Se (2)) and the well known precursor clusters [Fe₃(CO)₉( ₃-Y)₂] (Y=S (3) or Se (4)) in toluene were measured using Z-scan and ARINS techniques respectively. Compounds 1 and 2 possess nearly three times the _R values of their corresponding precursor compounds, 3 and 4. The results suggest a rich potential of mixed-metal, mixed-nonmetal class of clusters as materials exhibiting large nonlinearity.     

Tetrahedral and heteronuclear transition metal clusters through isolobal displacements and functional transformations

The isolobal reaction of the tetrahedral cluster Ph₂C₂Co₂(CO)₆with ⁵-CHOC₅H₄(CO)₃MNa (M = Mo, W) yields ⁵-CHOC₅H₄MCoC₂Ph₂(CO)₅ [(1) M = Mo, (2) M = W], whereas M–M singly-bonded dimers [⁵-RC₅H₄- M(CO)₃]₂ [M = Mo, R = Ac; M = Mo, W, R = CHO] react with Co₂(CO)₈ to give ⁵-AcC₅H₄MoCo₃(CO)₁₁ (7) and ⁵-C₅H₅MCo₃(CO)₁₁ [(8) M = Mo, (9) M = W], respectively. While (1) and (2) react with 2,4-dinitrophenylhydrazine to give phenylhydrazone derivatives ⁵-2,4-(NO₂)₂C₆H₃NHN=CHC₅H₄MCoC₂Ph₂(CO)₅ [(3) M = Mo, (4) M = W], treatment of ⁵-AcC₅H₄MCoFe(CO)₈(₃-S) with 2,4-dinitrophenylhydrazine produces corresponding derivatives ⁵-2,4-(NO₂)₂C₆H₃NHN=C(Me)C₅H₄MCoFe(CO)₈(₃-S) [(5) M = Mo, (6) M = W]. In addition, the cyclopentadienylformaldehyde ligand in the ⁵-CHOC₅H₄MoCoFe(CO)₈(₃-S) cluster can be decarbonylated in the presence of Co₂(CO)₈ to give the parent cluster ⁵-C₅H₅MoCoFe(CO)₈(₃-S)(10). This observation, together with the formation of (8) and (9) in the presence of Co₂(CO)₈ can be explained by the proposed mechanism.     

Reactions of 1,4-difeffocenylbuta-1,3-diyne and 1,4-diphenylbut-l-en-3-yne with Ru3(CO)12. Crystal structure of Ru3(CO)8(μ3-η-1-η1-η4-η2-C4Ph2(CH=CHPh)2)

Diyne FcCmCC.CFc (Fc is ferrocenyl) reacts with Ru₃(CO)₁₂ in boiling hexane to yield binuclear complexes Ru₂ and Ru₂(CO)₆(C₄Fc₂(C=CFc)₂C=O) containing ruthenacyclopentadiene and diruthenacycloheptadienone rings, respectively. The isomerism of the complexes is due to the different ways of coupling of the alkyne fragments of the diyne, namely, head-to-head, head-to-tail or tail-to-tail. The reaction of enyne PhC=CCH=CHPh with Ru₃(CO)₁₂ under similar conditions gives isomeric binuclear complexes Ru₂(CO)₆(C₄Ph₂(CH=CHPh)₂) and trinuclear clusters Ru₃(CO)₆(w-CO)₂(C₄Ph₂(CH=CHPh)₂) and Ru₃(CO)₈(₃-,¹-¹-⁴-² C₄Ph₂(CH=CHPh)₂). The structure of the latter was determined by X-ray diffraction analysis. The Ru₃ triangle coordinates eight terminal CO groups and the organic ligand resulting from the head-to-head dimerization of enyne molecules; the ruthenacyclopentadiene moiety is ⁴-coordinated to the Ru(CO)₂ group, and the third ruthenium atom is 2-bound to one of the PhCH=CH groups.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1261–1267, May, 1996.