Acetylenic derivatives of metal carbonyls of the triad Fe,Ru, Os—XI Mass spectra of some binuclear complexes

The mass spectra of the following acetylenic derivatives of iron, ruthenium and osmium carbonyls are reported: the iron compounds Fe₂(CO)₆[C₂(C₆H₅)s₂]₂, Fe₂(CO)₆[C₂(CH₃)₂]₂ and Fe₂(CO)₆[C₂(C₂H₅)₂]₂, the ruthenium compounds Ru₂(CO)₆[C₂(C₆H₅)₂]₂, and Ru₂(CO)₆[C₂(CH₃)₂]₂ and the osmium compounds Os₂(CO)₆[C₂(C₆H₅)₂]₂, Os₂(CO)₆[C₂HC₆H₅]₂ and Os₂(CO)₆[C₂(CH₃)₂]₂. Iron compounds exhibit breakdown schemes where binuclear, mononuclear and hydrocarbon ions are present. On the other hand, ruthenium and osmium compounds fragment in a similar way and give rise to singly and doubly charged binuclear ions. Phenylic derivatives of ruthenium and osmium also give weak triply charged ions. The results are discussed in terms of relative strengths of the metal-metal and metal-carbon bonds.     

Synthesis of cationic dialkylgold(III) complexes: nature of the facile reductive elimination of alkane

A series of gold(III) cations of the type cis-[CH₃)₂AuL₂]⁺ X^? where L  Ph₃, PMePh₂, PMe₂Ph, PMe₃, AsPh₃, AsPh₃, SbPh₃, $\text{1}\text{2}$H₂NCH₂CH₂NH₂, $\text{1}\text{2}$ Ph₂PCH₂CH₂-PPh₂, $\text{1}\text{2}$ Ph₂AsCH₂CH₂AsPh₂, and $\text{1}\text{2}$o-C₆H₄(AsMe₂)₂ and X  BF₄^?, PF₆^?, ClO₄^?, and F₃CSO₃^? has been prepared. In addition, the cis complexes [(CH₃)(CD₃)-Au(PPh₃)₂]F₃CSO₃, [(C₂H₅)₂Au(PPh₃)₂]F₃CSO and [(n-C₄H₉)₂Au(PPh₃)₂]F₃-CSO₃ have been synthesized. All have been characterized by PMR, Raman and infrared spectroscopy. These [R₂AuL₂]X compounds yield only ethane, butane, or octane via reductive elimination, and no disproportionation is observed. The alkane eliminations have been studied in CHCl₃, CH₃Cl₂, and CH₃COCH₃ solution as a function of temperature, concentration of the complex, and concentration of added ligand L. Elimination is fastest when L is bulky (PPh₃ > PMePh₂ > PMe₂Ph > PMe₃), decreases in the sequence SbPh₃ > AsPh₃ > PPh₃, is slow with chelating ligands, is inhibited by excess ligand, and there is small anion effect as X is varied. As R is varied, the rate of elimination decreases Bu ? Et > Me. An intramolecular dissociative mechanism is proposed which involves rapid elimination of alkane from an electron deficient dialkylgold(III) complex with nonequivalent gold—carbon bonds and produces the corresponding [AuL₂]X complex.     

Synthesis of Inorganic Structural Isomers By Diffusion‐Constrained Self‐Assembly of Designed Precursors: A Novel Type of Isomerism

The structure of precursors is used to control the formation of six possible structural isomers that contain four structural units of PbSe and four structural units of NbSe₂: [(PbSe)_1.14]₄[NbSe₂]₄, [(PbSe)_1.14]₃[NbSe₂]₃[(PbSe)_1.14]₁[NbSe₂]₁, [(PbSe)_1.14]₃[NbSe₂]₂[(PbSe)_1.14]₁[NbSe₂]₂, [(PbSe)_1.14]₂[NbSe₂]₃[(PbSe)_1.14]₂[NbSe₂]₁, [(PbSe)_1.14]₂[NbSe₂]₂[(PbSe)_1.14]₁[NbSe₂]₁[(PbSe)_1.14]₁[NbSe₂]₁, [(PbSe)_1.14]₂[NbSe₂]₁[(PbSe)_1.14]₁[NbSe₂]₂[(PbSe)_1.14]₁[NbSe₂]₁. The electrical properties of these compounds vary with the nanoarchitecture. For each pair of constituents, over 20 000 new compounds, each with a specific nanoarchitecture, are possible with the number of structural units equal to 10 or less. This provides opportunities to systematically correlate structure with properties and hence optimize performance.     

On the properties of binuclear cyclopentadienyl-fulvalene-nitrene complexes of Nb

The properties of (η⁵:η⁵-C₅H₄C₅H₄)(C₅H₅)₂Nb₂(μ-NC₆H₅)₂ (I) have been investigated. Reaction of I with acids (HCl, H₂SO₄ and CX₃COOH) includes diprotonation to form the dication, [(η⁵:η⁵-C₅H₄C₅H₄)(C₅H₅)₂Nb_2^? (μ-NC₆H₅)₂H₂]²⁺ (II). The process is reversible and the initial neutral compound I may be recovered under the action of a base. The protonated compound II may lose NC₆H₅ ligands as C₆H₅NH₃⁺; the paramagnetic product of the dissociation (C₅H₄C₅H₄)(C₅H₅)₂Nb₂Cl₄ (III) has been isolated.     

Mass spectra of organometallic compounds—VII; Organonitrogen derivatives of metal carbonyls

The positive-ion mass spectra of the following organonitrogen derivatives of metal carbonyls are discussed: (i) The compounds NC₅H₄CH₂Fe(CO)₂C₅H₅, NC₅H₄CH₂COMo(CO)₂C₅H₅, NC₅H₄CH₂W(CO)₃C₅H₅, NC₅H₄CH₂COMn(CO)₄, C₅H₁₀NCH₂CH₂Fe(CO)₂C₅H₅, (CH₃)₂NCH₂CH₂COFeCOC₅H₅ and (CH₃)₂NCH₂CH₂COMn(CO)₄ obtained from metal carbonyl anions and haloalkylamines, (ii) The isocyanate derivative C₅H₅Mo(CO)₃CH₂NCO; (iii) The arylazomolybdenum derivatives RN₂Mo(CO)₂C₅H₅ (R ? phenyl, p-tolyl, or p-anisyl); (iv) The compound (C₆H₅N)₂COFe₂(CO)₆ obtained from Fe₃(CO)₁₂ and phenyl isocyanate; (v) The N,N,N′,N′-tetramethylethylenediamine complex (CH₃)₂NCH₂CH₂N(CH₃)₂W(CO)₄. Further examples of eliminations of hydrogen, CO, and C₂H₂ fragments were noted. In addition evidence for the following more unusual processes was obtained: (i) Elimination of HCN fragments from the ions [NC₅H₄CH₂MC₅H₅]⁺ to give the ions [(C₅H₅)₂M]⁺ (M ? Fe, Mo and W); (ii) Conversion of C₅H₅Mo(CO)₃CH₂NCO to C₅H₅Mo(CO)₂CH₂NCO within the mass spectrometer; (iii) Elimination of N₂ from [RN₂MoC₅H₅]⁺ to give [RMoC₅H₅]⁺; (iv) Novel eliminations of HNCO, FeNCO, and C₆H₅NC fragments in the mass spectrum of (C₆H₅N)₂COFe₂(CO)₆; (v) Facile dehydrogenation of the N,N,N′,-N′-tetramethylethylenediamine ligand in the complex (CH₃)₂NCH₂CH₂N(CH₃)₂W(CO)₄.     

Phase diagrams of binary systems of alkylammonium tetrachlorometallates(II)

The phase diagrams of four binary systems (C₁₀H₂₁NH₃)₂CoCl₄?(C₁₆H₃₃NH₃)₂CoCl₄, (C₁₂H₂₅NH₃)₂CoCl₄?(C₁₆H₃₃NH₃)₂CoCl₄, (C₁₀H₂₁NH₃)₂ZnCl₄?(C₁₆H₃₃NH₃)₂ZnCl₄ and (C₁₂H₂₅NH₃)₂ZnCl₄?(C₁₆H₃₃NH₃)₂ZnCl₄ were investigated by means of DSC. These six compounds and their binary mixtures can retain energies between 74 and 115 J/g during solid-state transformations at temperatures between 70 and 105°C, and they are therefore being considered for potential use in solar energy systems.     

The synthesis and structure of triphenylsiloxycyclotriphosphazenes

The triphenylsiloxy-substituted cyclotriphosphazenes, N₃P₃Cl₅OSiPh₃, gem-N₃P₃Cl₄(OSiPh₃)₂, N₃P₃(OSiPh₃)₆, and N₃P₃(OPh)₅OSiPh₃, have been prepared. The synthesis of gem-N₃P₃Cl₄(OSiPh₃)₂ involves the reaction of (NPCl₂)₃ with Ph₃SiONa to form the intermediates gem-N₃P₃Cl₄(OSiPh₃)₂(ONa) and gem-N₃P₃Cl₄(ONa)₂, which yield gem-N₃P₃Cl₄(OSiPh₃)₂ when treated with Ph₃SiCl. The compounds N₃P₃Cl₅OSiPh₃ and N₃P₃(OSiPh₃)₀ are formed by the condensation reactions of N₃P₃Cl₅OBuⁿ and N₃P₃(OBuⁿ)₆, respectively, with Ph₃SiCl. The compound N₃P₃(OPh)₅OSiPh₃ is synthesized by the reaction between N₃P₃(OPh)₅Cl and Et₃SiONa to first give the intermediate N₃P₃(OPh)₅ONa, which yields N₃P₃(OPh)₅OSiPh₃ when reacted with Ph₃SiCl. The structural characterization and properties of these compounds are discussed. The crystal and molecular structure of gem-N₃P₃Cl₄(OSiPh₃)₂ has been investigated by single-crystal X-ray diffraction techniques. The crystals are monoclinic with the space group P2₁/c with a = 16.850(8), b = 12.829(4), c = 18.505(15) Å, and β = 101.00(6)° with V = 3927 ų and Z = 4. © 1996 John Wiley & Sons, Inc.     

Preparation of nanocrystalline BiFeO3 and kinetics of thermal process of precursor

The Bi₂Fe₂(C₂O₄)₅·5H₂O was synthesized by solid-state reaction at low heat using Bi(NO₃)₃·5H₂O, FeSO₄·7H₂O, and Na₂C₂O₄ as raw materials. The nanocrystalline BiFeO₃ was obtained by calcining Bi₂Fe₂(C₂O₄)₅·5H₂O at 600 °C in air. The precursor and its calcined products were characterized by thermogravimetry and differential scanning calorimetry, FT-IR, X-ray powder diffraction, and vibrating sample magnetometer. The data showed that highly crystallized BiFeO₃ with hexagonal structure [space group R3c(161)] was obtained when the precursor was calcined at 600 °C in air for 1.5 h. The thermal process of the precursor in air experienced five steps which involved, at first, the dehydration of an adsorption water molecule, then dehydration of four crystal water molecules, decomposition of FeC₂O₄ into Fe₂O₃, decomposition of Bi₂(C₂O₄)₃ into Bi₂O₃, and at last, reaction of Bi₂O₃ and Fe₂O₃ into hexagonal BiFeO₃. Based on Starink equation, the values of the activation energies associated with the thermal process of Bi₂Fe₂(C₂O₄)₅·5H₂O were determined. Besides, the most probable mechanism functions and thermodynamic functions (ΔS ^≠, ΔH ^≠, and ΔG ^≠) of thermal processes of Bi₂Fe₂(C₂O₄)₅·5H₂O were also determined.     

Origin of the yellow color of complex nickel oxides

Single-crystal optical absorption spectra of NiO, NiTiO₃, NiWO₄, NiV₂O₆, NiNb₂O₆, Ni₂SiO₄, Ni₃V₂O₈, LiNiPO₄, Li₂Ni₂Mo₃O₁₂, SrNiTeO₆, LiScSiO₄:Ni, MgSiO₃:Ni, and (Mg,Ni)₂SiO₄ are presented for the purpose of comparing the spectra of yellow and green Ni²⁺ compounds. Powder spectra of NiTiO₃, NiWO₄, NiV₂O₆, NiNb₂O₆, and Ni₃V₂O₈ in the ultraviolet region help elucidate the more intense charge transfer bands. Bright yellow color results when Ni²⁺ is in a six-coordinated site significantly distorted from octahedral symmetry. Increased absorption intensity occurs when the metal ion d-d bands are in proximity to an ultraviolet charge transfer band.     

Mass spectra of monohapto-cyclopentadienyl derivatives of group IVB elements

Dissociative ionisation of organometallic cyclopentadiene derivatives containing one, two or three M(CH₃)₃ groups (M  Si, Ge, Sn) has been studied.Among the monometallated compounds, C₅H₅Si(CH₃)₂Cl, C₅H₅Si(CH₃)₂OCH₃ and (C₅H₅)₄Sb have also been investigated. To verify fragmentation patterns, the spectra of deuterated compounds such as C₅D₅Si(CH₃)₃, C₅D₅Sn(CH₃)₃, C₅D₄Si₂(CH₃)₆ and C₅D₃Si₃)₉ have been measured. Dissociative ionisation of h¹-cyclopentadienyl derivatives has been shown to differ essentially from that of h⁵-compounds.     

Symmetry and topology code of cluster self-assembly of icosahedral framework structures of boron and borides

The topological types of suprapolyhedral clusters composed of i-B₁₂ icosahedra have been modeled. The models of icosahedral supraclusters have been used in analysis of the crystal structures of boron and borides (the TOPOS program package). To identify nanocluster precursors in crystal structures, there have been used special algorithms for partitioning structural graphs into disjoint substructures and constructing a basis 3D network of the structure as a graph with the nodes corresponding to the positions of the centroids of the cluster precursors. The cluster self-assembly have been modeled for 25 types of icosahedral framework structures of boron—B₁₂-hR ₁₂, (B₁₂)2(B₂)₂-oP ₂₈, (B₁₂)₄B₂-P50, B₁₉₆-tP ₁₉₆, and B₃₃₃-hR ₃₃₃; binary borides—(B₁₂)O₂-hR ₁₄, (B₁₂)P₂-hR ₁₄, and (B₁₂)(CBC)-hR ₁₅; templated metal borides—Na₂(B₁₂)₂B₆-oI ₆₄, Mg₂(B₁₂)B₂-oI ₆₈, Tb(B₁₂)(B₄)-mI ₆₀, Al₄(B₁₂)₄B₈-oC ₈₈, (B₁₂)₄(Si4)₄-oI ₆₄, (B₁₂)₄B₂Be₄-tP ₅₈, Ti₂(B₁₂)₄B₂-tP ₅₂, Sc₁₂B₁₈₀-tP ₁₉₂, Cu₄Sc₁₂B₁₈₀-tP ₁₉₂, Si_1.5Sc₉B₁₇₈-tP ₂₁₆, Mg₂₈B₃₆₀-oP ₃₈₈, Al₂₈B₃₅₂-oP ₃₈₄, Si₂₈B₃₅₂-oP ₃₀₆, Y₂₄(B₁₅₆)₈(B₃₉)₈-cF1944, Sc₁₀B₃₁₅-hR339, and Li₂₄B₃₁₅-hR336. The symmetry and topology code of the crystal structure self-assembly from nanocluster precursors in the form of primary chain → microlayer → microframework has been completely restored. Frequency analysis of various topological and symmetry pathways for the formation and evolution of cluster precursors makes it possible to elucidate crystal-formation trends in inorganic systems at the microscopic level.     

Formation of supramolecular complexes in reactions of adduct formation of zinc diethyldithiocarbamate with morpholine. Molecular structures and thermal properties

A supramolecular compound of the general formula [Zn{NH(CH₂)₄O} {S₂CN(C₂H₅)₂}₂]₄ · NH(CH₂)₄O · C₂H₄{N(CH₂)₄O}₂ (I) was obtained and examined by X-ray diffraction analysis and thermography. According to X-ray diffraction data, the crystal lattice of compound I shows an unusual alternation of two independent centrosymmetric supramolecular complexes [Zn{NH(CH₂)₄O} {S₂CN(C₂H₅)₂}₂]₂ · C₂H₄{N(CH₂)₄O}₂ (Ia) and [Zn{NH(CH₂)₄O} {S₂CN(C₂H₅)₂}₂]₂ · NH(CH₂)₄O (Ib). Either complex includes two molecules of an adduct of bis(diethyldithiocarbamato)zinc with morpholine and outer-sphere molecules of 1,2-dimorpholinoethane or morpholine. Adduct molecules are structurally nonequivalent in pairs and linked with solvate molecules by hydrogen bonds. The calculated geometries of the zinc polyhedra are intermediate between trigonal bipyramid and tetragonal pyramid. Thermal decomposition of supramolecular compound I proceeds through desorption of the outer-sphere and coordinated organic molecules; in the final step, defragmentation of the dithiocarbamate part gives zinc sulfide.     

Modeling of the molecular and electronic structures of some mono- and biosmium complexes of fullerene C60

The modeling of the molecular and electronic structures of the following mono- and biosmium complexes of fullerene C₆₀ was performed by quantum chemical methods (MNDO/PM3 and DFT/PBE): (??²-C₆₀)[Os(PPh₃)₂(CO)CNMe], (??²,??²-C₆₀)[Os(PPh₃)₂(CO)(CNMe)]₂, (??²-C₆₀)[Os(PH₃)₂(CO)H], (??²,??²-C₆₀)[Os(PH₃)₂(CO)H]₂, (??²-C₆₀)[Os(PH₃)₂(CO)CNMe], (??²,??²-C₆₀)[Os(PH₃)₂(CO)CNMe]₂, and (5-C₆₀H₅)[Os(C₅H₅)], (5, 5-C₆₀H₁₀)[Os(C₅H₅)]₂.The osmium atoms in the first six complexes are ??²-coordinated by fullerene C₆₀. In the last two complexes, the ??⁵-coordination mode is observed. The structures of the radical anions of these complexes were calculated. The energies of the frontier orbitals were evaluated. The acceptor properties of the complexes are discussed. The electron affinities were estimated in two ways: from the energy of the lowest unoccupied molecular orbital (LUMO) and as the energy difference between the neutral molecule and its radical anion.     

Chalcogenolato-di-thiocarbamato-complexes of zinc: The X-ray single crystal structures of pyridine adducts

Novel mixed complexes 2,4,6-Me₃C₆H₂SZnS₂CNEt₂ (1), 2,4,6-Me₃C₆H₂SeZnSe₂CNEt₂ (2) and their pyridine adducts ([Zn(SC₆H₂Me₃-2,4,6)₂(C₅H₅N)₂] (3), [Zn(SeC₆H₂Me₃-2,4,6)₂(C₅H₅N)₂] (4) and (Et₂CNSe₂)₂Zn.NC₅H₅ (5) and (Et₂CNS₂)₂Zn.NC₅H₅ (6) have been synthesised and characterised. The X-ray single crystal structures of (4), (5) and (6) have been determined.     

Synthesis of multiply-bonded dichromium complexes with a variety of formamidinate ligands

A series of dichromium tetraformamidinate complexes with (ArNCHNAr)⁻ where Ar is X₂C₆H₃ or XC₆H₄ and X is the remote substituent 3,5-Cl₂, 3,4-Cl₂, p-Cl, p-CF₃, m-CF₃, p-OCH₃ or m-OCH₃ has been synthesized, and the structures of four of the compounds determined by X-ray crystallography. The Cr–Cr bond distances of the complexes structurally characterized are 1.9072(10) Å [Cr₂((p-ClC₆H₄N)₂CH)₄], 1.9162(10) Å [Cr₂((3,5-Cl₂C₆H₃N)₂CH)₄], 1.9018((8) Å [Cr₂((m-CF₃C₆H₄N)₂CH)₄ ], and 1.9178(11) Å [Cr₂((m-OCH₃C₆H₄N)₂CH)₄]. ¹H NMR spectroscopy and electrochemistry were performed on the series. The diamagnetic anisotropy of the Cr–Cr bond was calculated from X-ray crystallographic and ¹H NMR data and correlates with the Hammett constant of the formamidine ligands.     

Reactions of metal carbonyl derivatives X. The synthesis and reactivity of some dinuclear derivatives of iron containing both bridging carbonyls and bridging phosphido or sulphido groups

The tertiary phosphine π-C₅H₅Fe(CO)₂P(C₆H₅)₂ reacts with a suspension of Fe₂(CO)₉ in benzene to give the dinuclear complex π-C₅H₅Fe₂P(C₆H₅)₂(CO)₆. This compound is also obtained by nucleophilic attack of [π-C₅H₅Fe(CO)₂]⁻ on Fe(CO)₄-[P(C₆H₅)₂Cl] in tetrahydrofuran. Irradiation of a benzene solution of π-C₅H₅Fe₂-P(C₆H₅)₂(CO)₆ with ultraviolet light affords π-C₅H₅Fe₂P(C₆H₅)₂(CO)₅ which contains both a bridging carbonyl and a bridging phosphido group. The unstable bridged sulphido derivatives π-C₅H₅Fe₂SR(CO)₆ (R = CH₃ and C₆H₅) and π-C₅H₅Fe₂(t-C₄H₉S)(CO)₅ are similarly obtained employing π-C₅H₅Fe(CO)₂SR as ligand. The reactions of π-C₅H₅Fe₂P(C₆H₅)₂(CO)₅ with tertiary phosphines and phosphites yield three types of products depending on the reaction conditions and the ligand involved. Examples include π-C₅H₅Fe₂P(C₆H₅)₂(CO)₄P(C₆H₅)₃, a mono-substituted derivative of π-C₅H₅Fe₂P(C₆H₅)₂(CO)₅, and π-C₅H₅Fe₂P(C₆H₅)₂(CO)₅P(C₂H₅)₃ and π-C₅H₅Fe₂P(C₆H₅)₂(CO)₄[P(OCH)₃)₃]₂, mono- and bis-substituted derivatives of π-C₅H₅Fe₂P(C₆H₅)₂(CO)₆, respectively. The reaction of π-C₅H₅Fe₂P(C₆H₅₂(CO)₅ with (C₆H₅)₂PCH₂P(C₆H₅)₂ in benzene under reflux affords [π-C₅H₅Fe₂P(C₆H₅)₂(CO)₄](C₆H₅)₂PCH₂P(C₆H₅)₂ in which the ditertiary phosphine bridges two iron atoms.     

Metallation studies of organofunctional trisiloxanes

Summary The organofunctional trisiloxanes Me₃SiOSiMe(R)OSiMe₃ [R=(CH₂)₂PPh₂, (CH₂)₃C₅H₄N, (CH₂)₃CN, (CH₂)₂Ph, (CH₂)₂SPh, CH=CH₂ and CH₂CH=CH₂] have been reacted with metal halide and-carbonyl moieties in order to determine the coordination preferences of materials being used as models for metallated longchain linear functionalised polysiloxanes. The products [Me₃SiOSiMe(R)OSiMe₃]₃ML_n [R=(CH₂)₂PPh₂, ML_n=RhCl],cis-[Me₃SiOSiMe(R)OSiMe₃]₂ML_n [R=(CH₂)₂PPh₂ or (CH₂)₃C₅H₄N, ML_n=Mo(CO)₄],trans-[Me₃SiOSiMe(R)OSiMe₃]₂ML_n[R=(CH₂)₂PPh₂, ML_n=NiCl₂, PdCl₂, PtCl₂ and [Rh(CO)Cl] and [Me₃SiOSiMe(R)OSiMe₃]ML_n [R=(CH₂)₂PPh₂, ML_n=Mo(CO)₃(2,2-bipyridine); R=(CH₂)₂Ph, ML_n=Mo(CO)₃; R=(CH₂)₃C₅H₄N, (CH₂)₃CN, or (CH₂)₂SPh, ML_n=Rh(CO)₂Cl; R=CH=CH₂ or CH₂CH=CH₂, ML_n=Fe(CO)₄] have been isolated and characterised spectroscopically in the course of these studies.     

The synthesis and reactivity of rhenocene

Oxidation of lithiodicyclopentadienylrhenium by organic carbonyl compounds gives the complex (C₂₀H₂₀Re₂). Spectroscopic data show that this complex consists of two rhenocene fragments, {(C₅H)₅Re}, linked by a metal-metal bond, and so that it must be represented as a dimer of rhenocene, {(C₅H₅)Re}₂. Reaction of the dimer with benzyl bromide gives {(C₅H₅)₂ReCH₂C₆H₅} and {(C₅H₅₂ReBr}, while thermolysis gives the new dimeric complex {(C₅H₅)₂(C₅H₄)₂Re₂} and two equivalents of {(C₅H₅)ReH} and photolysis (λ ? 410 nm) gives [{η⁴- (C₅H₆)(C₅H₅)Re}{η⁵,η¹-(C₅H₄)(C₅H₅)Re}].     

Metallation of aliphatic carbon atoms: II,syntheses and characterization of the cyclopalladated complexes of N,N-dimethylneopentylamine

N,N-Dimethylneopentylamine reacts with Pd(MeCO₂)₂ to give a novel trinuclear cyclopalladated complex [Me₂NCH₂CMe₂CH₂Pd(μ-MeCO₂)₂Pd(μ-MeCO₂)₂PdCH₂CMe₂CH₂NMe₂]?-0.5C₆H₆ (I). The reaction of I with PPh₃ affords both trans-[Pd(MeCO₂)₂(PPh₃)₂] (II) and [Pd(CH₂CMe₂CH₂NMe₂)(MeCO₂)(PPh₃)] (III). The reaction of III with LiCl yields a mononuclear cyclopalladated complex, [Pd(CH₂CMe₂CH₂NMe₂)Cl(PPh₃)] (IV).     

Temperature dependence of the mixed-valence state of57Fe-atoms produced in57Co-Labelled oxo-centered trinuclear iron acetate complexes

Emission Mössbauer spectra of mixedvalence trinuclear complexes,⁵⁷Co-labelled [CoFe₂O(CH₃CO₂)₆(H₂O)₃] and [CoFe₂O(CH₃CO₂)₆ (py)₃]py were compared with that of [CoCr₂O(CH₃CO₂)₆ (py)₃]py. It was found that the⁵⁷Fe atoms produced in⁵⁷Co-labelled [CoFe₂O(CH₃CO₂)₆(H₂O)₃] and [CoFe₂O(CH₃CO₂)₆ (py)₃]py showed a temperature-dependent mixed-valence state as observed in the absorption Mössbauer spectra of [Fe₃O(CH₃CO₂)₆ (H₂O)₃] and [Fe₃O(CH₃CO₂)₆ (py)₃]py, respectively, while⁵⁷Co-labelled [CoCr₂O(CH₃CO₂)₆ (py)₃]py showed a temperature-independent divalent iron/II/ state. The results indicate that the decayed atoms keep their position at the sites of original⁵⁷Co atoms and that the valence electrons are transferred through the intramolcular bondings.