Molecular Complexes of Fullerenes C60 and C70 with Saturated Amines

New molecular complexes of fullerenes C₆₀ and C₇₀ with leuco crystal violet (LCV, 1-3); leucomalachite green (LMG, 4-6); crystal violet lactone (CVL, 7); N,N,N′,N′-tetrabenzyl-p-phenylenediamine (TBPDA, 8, and 9); N,N,N′,N′-tetramethyl-p-phenylenediamine (TMPDA, 10, and 11); triphenylamine (TPA, 12, and 13); and substituted phenotellurazines (EPTA and TMPTA, 14, and 15) have been synthesized. Crystal structures have been solved for C₆₀ complexes with LMG (5, 6) TBPDA (8), TMPDA (10), and TPA (12). The C₆₀ molecules form closely packed double layers in 5 and 6, hexagonal layers in 10 and quasi-three-dimensional layers in 8 and 12. The substitution of disordered solvent molecules in the complexes with LMG (4, 5) by naphthalene ones results in the ordering of the C₆₀ molecules. According to IR-, UV-visible-NIR and ESR-spectroscopy the complexes have a neutral ground state. The spectra of 1-8, and 10 show intense charge transfer bands in the visible and NIR-range. On photoexcitation by white light (light-induced ESR (LESR) spectroscopy), 1 and 10 were shown to have an excited ionic state. The LESR signals were generated at light energies <2.25 eV indicating that the excited states in the complexes are realized mainly by direct charge transfer from donor to the C₆₀ molecule.     

Carbonyl derivatives of phthalocyaninatoiron(II), especially those containing group VI axial donor atoms. Crystal and molecular structure of carbonyl(N,N-dimethylformamide)phthalocyaninatoiron(II) and mössbauer studies of some of the products

The carbonyl adduct of phthalocyaninatoiron(II), FePc, with N,N-dimethylformamide (DMF) as axial ligand, FePc(CO)DMF, was prepared by the reaction of iron carbonyls, Fe(CO)₅ or Fe₂(CO)₉, with o-phthaalonitrile in DMF as solvent. Several carbonyl adducts of FePc of general formula FePc (CO)L are reported, with L being a ligand with oxygen, sulphur and nitrogen donor atoms (L = tetrahydrofuran, H₂O, CH₃OH, dimethylsulphoxide, tetrahydrothiophene, ammonia, n-propylamine, diethylamine, triethylamine). The crystal and molecular structure of FePc(CO)DMF·DMF was investigaed by X-ray diffraction methods. The compound has a monoclinic unit cell and space group P2₁/n, a 9.86(1), b 17.35(3), c 19.79(4) », β 87.9(2)°, Z = 4, U 3383 »³, D₃ 1.458 g cm^?3. The iron atom is hexacoordinated to the four inner nitrogen atoms of the macrocyle, to carbon monoxide (Fe—C distance 1.72(2) ») and to DMF (Fe—O distance 2.07(1) »). The extra DMF occupies lattice sites. All of the compounds reported in this paper are substantially diamagnetic. Mössbauer spectra show typical isomer shift parameters for the bis-adducts and for the carbonyl adduct, substantially independent of the nature of the axial ligand. The quadrupole splitting parameter of the carbonyl adducts is strongly affected by the nature of the axial ligand.     

Basicity of transition metal carbonyl complexes : IX. An infrared study of lewis acid reactions with cyclopentadienyl and arene derivatives of groups VI and VII transition metal carbonyls and nitrosyls

The different courses of the interactions of cyclopentadienyl and arene derivatives of Group VI and VII transition metal carbonyl and transition complexes with Lewis acids, in solutions, have been studied by IR spectroscopy.The information of adducts involving the metal atom was observed for CpRe(CO)₂L (L = CO, PR₃) with SnCl₄, SnBr₄, TiCl₄; AreneM(CO)₃ (M = Cr, Mo, W) with SnCl₄, TiCl₄; and Ph₃PC₅H₄M(CO)₃ (M = Cr, Mo, W) with TiCl₄ and AlCl₃. Complexes CpM(CO)₂NO and CpM(CO(NO)PPh₃, depending on thier donor and acceptor nature, form adducts involving the oxygen atoms of CO or NO groups or the metal atom. CpCr(NO)₂Cl reacts with Lewis acids via the chlorine atom. The relative basicity of the different sites in the complexes investigated is discussed.     

The single-crystal electron spin resonance spectra of bis chloro bis(N,N′-substituted urea)oxovanadium(IV) compounds diluted in the corresponding tris-chloro bis(N,N′-substituted)urea indium(III) compounds

Single crystal ESR spectra of VOCl₂L₂ (where L = N, N, N′, N′-tetramethyl urea (tmu), N, N′-dimethylethyleneurea, N, N′-dimethylpropyleneurea, tris(dimethylamino)phosphincoxide) diluted in the corresponding Inøcl₃L₂, at Q-band frequencies are reported. The ESR data are consitent with C₂ point symmetry for VOCl₂(tmu)₂ whilst the other compounds approximate very closely to this point symmetry. A rotation of the g and A tensor axes in the plane perpendicular to the terminal VO vector fall in the range 8–15° for the four compounds studied. The spin Hamiltonian parameters for VOCl₂(tmu)₂, in conjunction with the published polarized electronic absorption spectra, have been analysed via angular overlap calculations. For VOCl₂(tmu)₂ unusual ligand hyperfine splittings were observed. These were analysed by spectrum simulation in terms of two equivalent chlorine atoms where the chlorine hyperfine and nuclear quadrupole tensors are of comparable magnitude.     

Reaction of triflyl-imidazole with aldoximes: facile synthesis of nitriles and formation of novel aldoxime-bis(N-triflyl)-imidazole adducts

The synthetic utility of N-triflylimidazole as an in situ reagent for facile, high yielding, synthesis of various aliphatic, aromatic, and heteroaromatic nitriles from the corresponding aldoximes has been demonstrated. With benzaldoximes, in the presence of certain substitutents (2-F; 2-OMe; 3-CF₃; 2-Me-5-F) a different course of reaction was observed, leading instead to novel 1:1 aldoxime-bis(N-triflyl)imidazole covalent adducts, in which the aldoxime oxygen atom is bonded to the imidazole C-2 ring carbon. For these aldoximes, conversion to nitrile could be effected by reaction with Tf₂O in the absence of imidazole. The molecular structure of the adduct formed from 2-methyl-5-fluoro-benzaldoxime was confirmed by X-ray analysis. Plausible mechanisms for the formation of 1:1 covalent adducts have been considered. Various attempts to isolate such adducts via the reaction of an authentic sample of bis(N-triflyl)imidazolium trifate with aldoxime were unsuccessful. Remarkably, whereas isolated benzaldoxime adducts undergo deprotonation/methylation with NaH/MeI, an authentic sample of bis(N-triflyl)imidazolium triflate did not undergo H/Me exchange under these conditions. These transformations are discussed.     

On the mechanism of the Fe(CO)5-catalyzed Kbarasch reaction

Addition of BrCCl₃ to methylN-acryloyl-(S)-prolinate (1) catalyzed by Fe(CO)₅ or Fe(CO)₅-PPh₃ at 75–80 °C in benzene solution affords in good total yield methylN-((S)-2-bromo-3,3,3-trichlorobutyryl)-(S)-prolinate (2) and methylN-((R)-2-bromo-3,3,3-trichlorobutyryl)-(S)-prolinate (3) in an ～1.5 : 1 ratio, which does not depend on the catalytic system employed or its concentration. Catalysis by the Fe(CO)₅-PPh₃ system substantially increases the adducts yield.     

New chloro- and trifluoroacetato tricarbonylrhenium(I) complexes with a N,N′-bis(benzophenone)-1,2-diiminoethane Schiff base ligand: Spectral and structural studies

The reaction of Re(CO)₅Cl with the chelating ligand N,N′-bis(benzophenone)-1,2-diiminoethane (bz₂en) afforded the neutral fac-[Re(CO)₃(bz₂en)Cl]. The subsequent reaction with AgOCOCF₃ gave fac-[Re(CO)₃(bz₂en)OCOCF₃]. Their pseudooctahedral fac structures have been established by FTIR, UV–Vis, ¹H, ¹³C NMR and have been confirmed by X-ray diffraction analysis. The electrochemical behaviour of the investigated complexes has been studied by cyclic voltammetry.     

Generation of 15N labelled bis(polyfluoroalkyl) nitroxides and their hydrogen-abstraction reactions with alkanes,alkylbenzenes and aldehydes

Blue solutions containing ¹⁵ labelled bis(polyfluoralkyl) nitroxides and spin traps, polyfluoronitrosoalkanes, were conveniently made from the reactions of Na¹⁵NO₂ with polyfluoro-compounds, (R_FCO₂) and R_FSO₂Br in F113. It has been found that the nitroxides effected fast H-abstraction from alkanes, alkylbenzenes, aldehydes and the radicals derived from the substrates were in turn effectively trapped by R_F¹⁵NO to give ¹⁵N labelled spin adducts detectable by ESR. The bigger a_N(15_N) values as well as much simpler splittings of both the nitroxides and the spin adducts have made the kinetic studies of the H-abstraction and other radical reactions quite feasible.     

Metal complexes of 4,5-dimethylpyrazole-3-carboxaldehyde phenylthiosemicarbazone

Several new transition metal complexes derived from 4,5-dimethyl-3-carboxaldehyde phenyl- thiosemicarbazone, LH, have been synthesized. The complexes are of stoichiometry, [CoL₂]X, X = Cl⁻, Br⁻, ClO⁻₄ or NO⁻₃, [MnL₂] and [CuX_nL_m], X = Cl⁻, Br⁻, NCS⁻ or N⁻₃; n = 1 or 0; m = 1 or 2 and L = the anion of LH. All complexes have been characterized by elemental analysis, spectral (i.r., electronic, NMR, ESR) and magnetic measurements. The ligand acts as tridentate monobasic co-ordinated to the metal ion via azomethine, pyrazole (N²) nitrogen atoms and the thiolo-sulphur. The ligand field and ESR parameters are used to interpret the nature of bonding of LH with the metal ion, ground state and the ligand field strength of LH and the various co-ordinated simple ions. The coupling constants of various co-ordinated nuclei with copper (II) are estimated from ESR spectra of copper (II) complexes.     

ESR investigation of the substitution reactions in rhodium(I) complexes with spin-labeled ligands

A number of new spin-labelled Rh^I complexes containing both the 3,6-ditert-butyl-o-benzosemiquinone (3,6-SQ) fragment and n- and π-donor ligands have been prepared. The tetracoordinate derivatives of the composition L₂Rh-(3,6-SQ), where L  CO, P(OPh)₃, L  1/2 1,5-COD and the pentacoordinate complex (PPh₃)₂Rh(3,6-SQ)(CO) were isolated in individual state, the formation of other rhodium compounds was registered by ESR spectroscopy. The presence of an o-benzosemiquinolate ligand in the molecule with the unpaired electron located essentially on this fragment does not significantly influence on the reactivity of the metal ion in most cases; the n- and π-donor ligands exchange reactions studied by ESR confirm this fact. (PPh₃)₂Rh(3,6-SQ) has an abnormal distribution of spin density of the unpaired electron in the molecule, mostly located on the metal atom, this derivative bearing a close analogy to the rhodium(II) (d⁷) complexes.     

Borabenzene and pentafluoroborabenzene adducts with dinitrogen, xenon and krypton: A quantum-chemical study

Structural parameters of borabenzene and pentafluoroborabenzene molecules and their adducts with N₂, Xe, and Kr are calculated by the B3LYP quantum-chemical method. The adducts C₆F₅B·(N₂, Xe, Kr) are characterized by the formation energies 36, 26, and 8 kcal mol^?1, bond lengths 1.45, 2.23, and 2.21 Å, charges +0.2 (N₂), +0.4 (Xe), and +0.3 au (Kr), and dipole moments 2.8, 7.0, and 6.0 D, respectively. The adducts C₆H₅B · (N₂, Xe) have the total energies 18 and 11 kcal mol^?1, bond lengths 1.48 and 2.45 Å, charges +0.1 (N₂) and +0.3 au (Xe), and dipole moments 0.8 and 4.0 D, respectively. Unsubstituted borabenzene does not form a chemical bond with krypton.     

The reactions of [Fe2(η-C5H5)2(CO)4−n(CNMe)n] (n = 0–4) complexes with halogens and mercury(II) salts

Halogens, X₂, and HgY₂ (X = Cl, Br, I; Y = X, F, NO₃, BF₄) cleave the metalmetal bonds in [Fe₂(η-C₅H₅)₂(CO)_4−n(CNMe)_n] complexes (n = 0–4). Typically, e.g., when n = 2, X₂ electrophiles give [Fe(η-C₅H₅)(CO)(CNMe)X] (a) and [Fe(η-C₅H₅)(CO)(CNMe)₂]X (b) in relative yields which depend on X, the reaction solvent and n, but HgY₂ give equimolar amounts of [Fe(η-C₅H₅)(CNMe)₂Y] (c and [Fe(η-C₅H₅)(CO)₂HgY] only. Hg(CN)₂ reacts more slowly than other HgY₂, and [Hg(PPh₃)₂I₂] does not react at all. It is suggested that the reactions which give rise to products of type (a), (b) or (c) are all two-electron oxidation which proceed by way of adducts containing μ-CA → X₂ or μ-CA → HgX₂ groups (Ca = CO or CNMe). One of these adducts has been isolated, namely [Fe₂(η-C₅H₅)₂(CNMe)₂{μ-CN(Me)HgCl₂}₂] · CHCl₃.     

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

本文合成了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。     

An ESR study of photochemical reactions of Co2(CO)6(PBu3)2 with quinones and phenothiazine

The photochemical reactions of Co₂(CO)₆(PBu₃)₂ with various quinones and phenothiazine were studied by ESR. The results indicate that the photolysis of Co₂(CO)₆(PBu₃)₂ in the presence of o-quinones led to the observation of an ESR spectrum, showing a broad 8 or 12 groups of hyperfine lines due to interaction with cobalt (Co, 1 = 7/2). The results show that with o-quinones the cobalt radical adducts are formed via metal chelation to the carbonyl oxygens. However, when Co₂(CO)₆(PBu₃)₂ was irradiated in the presence of p-quinones, only the para-semiquinone radicals were observed. The photolysis of Co₂(CO)₆(PBu₃)₂ with phenothiazine in toluene yields phenothiazine radical. The sixteen and eighteen electrons rule have been used to account for these observations.     

Three-coordinate RhX[P(C6H11)3]2, their reactions with N2 and O2, and the trans-influence in RhX[P(C6H11)3]2L (X = anionic,L = neutral ligand)

Three-coordinate RhX(PCy₃)₂ complexes (X = F, Cl, Br, I; Cy = cyclohexyl) have been prepared from rhodium(I) cyclooctene compounds. RhCl(PCy₃)₂ is in equilibrium with its dimer. The complexes RhX(PCy₃)₂ (X = Cl, Br, I) form the adducts RhX(PCy₃)₂(N₂) with dinitrogen, the times for N₂-fixation being 4 days, 3 hours and 15 minutes respectively. The three-coordinate complexes form four-coordinate dioxygen adducts RhX(PCy₃)₂(O₂) which have unusually high ν(OO) at about 990 cm^?1. This high frequency is attributed to the four-coordination, which is exceptional for dioxygen complexes. From RhF(PCy₃)₂ carbonyl, ethene, and diphenylacetylene complexes RhX(PCy₃)₂L (X = F, Cl, Br, I, N₃, NCO, NCS; L = CO, C₂H₄, C₂Ph₂) (X = CN, NO₃, acetate; L = CO) have been prepared. The trans-influence of the anionic ligands on the infrared frequencies of the neutral ligands is discussed in terms of the different π-bonding properties of the X- and L-ligands.     

A new route to mer-Tricarbonyls of manganese(I) containing N-donor chelate ligands

It has been shown that new mer-tricarbonyls mer-[Mn(CO)₃L(tmed)]ClO₄, (tmed = N,N,N′,N′-tetramethylethylenediamine, L = P(OMe)₃, P(OEt)₃, P(O-iPr)₃) can be readily obtained from the reaction between fac-Mn(CO)₃(tmed)Br, AgClO₄, and L at room temperature, whereas at 0°C fac-isomers are produced. The opposite is the case for L = CN-t-Bu; mer-[Mn(CO)₃(CN-t-Bu)(tmed)]ClO₄ is observed at 0°C, and the fac-isomer is stable at 25°C.     

Synthesis, electrochemistry, and crystal and molecular structures of some molybdenum(0) arene derivatives with fluorinated and phenyl-substituted arene ligands

Compounds of general formula Mo(η⁶-arene)(CO)₃, arene=diphenyl, 1; 1,3,5-triphenylbenzene, 2; C₆H₅F, 3; C₆H₅CF₃, 4, have been prepared in good yields by reacting fac-Mo(CO)₃(DMF)₃, DMF=N,N-dimethylformamide, with BF₃ · OEt₂ and the appropriate arene. The crystal and molecular structures of 1, 3, and 4, are reported. The dinuclear derivative Mo₂(η⁶:η⁶-C₆H₅-C₆H₅)(CO)₆, 5, was obtained by thermal reaction of Mo(η⁶-toluene)(CO)₃ with Mo(η⁶-diphenyl)(CO)₃. An electrochemical study has been performed on the new complexes, showing that the dimolybdenum complex undergoes a single two-electron reduction at about the same potential as the corresponding dichromium complex, the molybdenum dianion being less stable than the chromium analogue.     

Iron complexes of N-allylbenzotriazoles

Sodium benzotriazolide reacts with π-C₃H₅Fe(CO)₃I to give 1-N-allylbenzotriazoletricarbonyliron (I). The same product and the isomeric complex, 2-N-allylbenzotriazoletricarbonyliron (II), have been prepared independently, from the corresponding N-allylbenzotriazoles and Fe₂(CO)₉. The IR, ¹H NMR, and mass spectra of the complexes are reported. The structure of isomer I has been determined by X-ray diffraction. The crystals are monoclinic, P2₁/c, a = 10.65(1), b = 9.95(1), c = 12.90(1) Å, β = 113.69(7)°, d_calc = 1.39 g cm^?3, Z = 4.     

Quantum-chemical investigation of reactions of (dialkylamino)ethynylphosphonates with amines

Structural parameters and molecular energies of diethyl piperidylethynylphosphonate, dimethyl (diethylamino)ethynylphosphonate, dimethyl[2-(t-butylamino)-2-(diethylamino)vinyl]phosphonate, N,N-diethyl-N′-t-butyl(dimethoxyphosphinoyl)acetamidine, dimethyl [2-(diethylamino)-2-(phenylamino)vinyl]phosphonate, N,N-diethyl-N′-phenyl(dimethoxyphosphinoyl)acetamidine, and the cations formed by protonation of the phosphinoyl group, nucleophilic carbon atom, or nitrogen were determined by means of B3LYP/6-311G(d₅,p)&;6-31G(d₅,p) quantum-chemical calculations. Acid-base properties of the related amines and their adducts with boron trifluoride in CCl₄ are estimated. The mechanism of the reactions of (dialkylamino)ethynylphosphonates with amines is discussed.     

Five- and six-coordinated transition-metal mixed-anion compounds containing the sterically constrained pyrazole-containing ligand 1,6-bis(3′,5′-dimethylpyrazol-1′-yl)-2,5-dimethyl-2,5-diazahexane

The dimethylpyrazole derivative of N,N′-dimethylethylenediamine, viz. 1,6-bis(3′,5′-dimethylpyrazol-l′-yl)-2,5-diazahexane (debd), forms coordination compounds with the transition-metal ions Co(II), Ni(II), Cu(II) and Zn(II) in the presence of a halide and a perchlorate anion of stoichiometry [M(debd)X(H₂O)_nClO₄ (n = 0 or 1). The ligand is always tetradentate. With cobalt and nickel six-coordinate compounds are formed. With copper and zinc five-coordinate compounds are formed. The compounds have been characterized by spectroscopic and magnetic methods (IR, ligand field, ESR and NMR).