Zinc Hydrazides and Alkoxyhydrazides: Organometallic Compounds with Novel Zn4N8, Zn4N6O and Zn4N4O2 Cage Structures

Tetrameric [{RZn(NHNMe₂)}₄] (R = Me, Et), the first organometallic zinc hydrazides to be described, have been prepared by alkane elimination from dialkylzinc solutions and N,N‐dimethylhydrazine. They were characterised by ¹H and ¹³C NMR and IR spectroscopy, mass spectrometry, elemental analysis and X‐ray crystallography. The compounds form asymmetric aggregates containing the novel Zn₄N₈ core; tetrahedra of Zn atoms bear the alkyl groups at Zn, with the triangular faces bridged by NHNMe₂ substituents. The NH groups are connected to two Zn atoms, and the NMe₂ groups to one. Hydrolysis of the compounds with water gives [(RZn)₄(OH)(NHNMe₂)₃] as products, which also were characterised as described above. Higher yields of these hydroxo clusters were achieved in one‐pot syntheses by reaction of dialkylzinc solutions with mixtures of N,N‐dimethylhydrazine and water. They contain Zn₄N₆O cages, in which one hydroxide in the tetrameric hydrazides described above replaces one NHNMe₂ group. Similar products can be prepared with alkoxy instead of hydroxy groups, in analogous one‐pot syntheses with alcohols. Alcoholysis of [EtZn(NHNMe₂)]₄ with methanol or ethanol gave zinc trishydrazide monoalkoxides, [(EtZn)₄(OR)(NHNMe₂)₃] (R = Me, Et), which have constitutions analogous to the monohydroxides. The organozinc bishydrazide bisalkoxides [(MeZn)₄(NHNMe₂)₂(OEt)₂] and [(EtZn)₄(NHNMe₂)₂(OEt)₂] were obtained in one‐pot reactions from dialkylzinc solutions with mixtures of the hydrazine and alcohol, and their crystal structures, confirmed by spectroscopic methods in solution, show an unsymmetrical aggregation with the novel Zn₄N₄O₂ cage structure.     

Synthesis and structure of diamine bis(phenolate) complexes containing the Ti(OEt)–O–Ti(OEt) function

Reaction of diamine-bis(phenol) ligands containing a mixture of N-methyl and N,N′-dimethyl-N,N-bis(2-hydroxy-3,5-dimethylbenzyl)ethylenediamine, H₂L¹ and H₂L³, with [Ti(OCHMe₂)₄ in absolute ethanol under reflux without exclusion of air and moisture gives [(L¹)Ti (OEt–O–Ti(OEt)(L¹)] (1). [(L³)Ti(OEt)–O–Ti(OEt)(L³)] (2) forms when the remaining solution containing [(L³)Ti(OEt)₂] (3) (characterised by X-ray crystallography) is hydrolysed with H₂O. For the N-methyl and N,N′-dimethyl ligand mixture H₂L² and H₂L⁴, which contain tert-butyl groups on the ortho-positions of the aryl rings, [(L²)Ti(OEt)–O–Ti(OEt)(L²)] (4) forms much more slowly and [(L⁴)Ti(OEt)₂] (5) does not hydrolyse when H₂O is added. When the N-protonated ligand N,N-bis(2-hydroxy-3-methyl-5-tert-butylbenzyl)ethylenediamine, H₂L⁵, is used, rapid hydrolysis to two isomers of [(L⁵)Ti(OEt–O–Ti(OEt)(L⁵)] (6) occurs without addition of water. For N,N-bis(2-hydroxy-3,5-di-tert-butylbenzyl)ethylenediamine, H₂L⁶, hydrolysis to [(L⁶)Ti(OEt)–O–Ti(OEt)(L⁶)] (7) occurs slowly when H₂O is added. For pendant NMe₂ ligand N,N-dimethyl-N′,N′-bis(2-hydroxy-3-methyl-5-tert-butylbenzyl)ethylenediamine, H₂L⁷, the hydrolysis reaction readily gives [(L⁷)Ti(OEt)–O–Ti(OEt)(L⁷)] (8) for which an X-ray crystal structure was obtained. The ortho-tert-butyl ligand derivative H₂L⁸ formed a complex analysing as [(L⁸)Ti(OEt)–O–Ti(OEt)(L⁸)] (9) which could not be studied further due to insolubility. Pendant pyridine ligand N-(2-pyridylmethyl)-N,N-bis(2′-hydroxy-3′-methyl-5′-tert-butylbenzyl)amine, H₂L⁹, apparently forms isomers of [(L⁹)Ti(OEt)–O–Ti(OEt)(L⁹)] and possibly [{(L⁹)Ti(O)}₂] from [(L⁹)Ti(OEt)₂] (10). The ortho-tert-butyl ligand derivative H₂L¹⁰ formed [(L¹⁰)Ti(OEt)–O–Ti(OEt)(L¹⁰)] (11) for which an X-ray crystal structure was obtained.     

1,1,3,3,3-Pentafluoro-2-pentafluorophenylpropene oxide. Precursor for novel phosphonates and ylides

1,1,3,3,3-Pentafluoro-2-pentafluorophenylpropene oxide reacted with triethyl phosphite to give the ylide C₆F₅(CF₃)C=P(OEt)₃. Hydrolysis yielded the phosphonate C₆F₅(CF₃)CHP(O)(OEt)₂, which was dehydrofluorinated using Et₃N · BF₃ to form the vinyl phosphonate C₆F₅(CF₂=)CP(O)(OEt)₂, a compound available also directly from the starting epoxide and diethyl trimethylsilyl phosphite. The vinyl phosphonate and diethyl trimethylsilyl phosphite furnished a 2:1 mixture of (Z) and (E) bisphosphonates together with fluorotrimethylsilane. Thermolylsis of the ylide gave diethyl phosphorofluoridate and 1,1-difluoro-2-pentafluorophenyl-but-1-ene. © 1997 John Wiley & Sons, Inc.     

The preparation of cobalt complexes containing simple sulphur-nitrogen ligands,S2N2H− and S3N−, from S4N4O2

Summary Reactions of Group VIII metal halides [CoCl₂, NiCl₂, K₂PdCl₄, PdCl₂(PhCN)₂ and PtCl₂] with tetrasulphurtetranitrogendioxide, S₄N₄O₂, have been investigated. The cobalt reaction yields Co(S₂N₂H)₂, Co(S₂N₂H)(S₃N) and Co(S₃N)₂. The usefulness of metal centres for trapping reactive sulphur-nitrogen centres is discussed.     

The reaction of <Emphasis Type="Italic">N</Emphasis>-sulfinyltrifluoromethanesulfonamide with triethylphosphate and triethylphosphite

The reaction of N-sulfinyltrifluoromethanesulfonamide CF₃SO₂NSO with triethylphosphate and triethylphosphite results in N-(trifluoromethanesulfonyl)triethoxyphosphazene CF₃SO₂N=P(OEt)₃, which upon heating is converted into the diethyl ester of N-trifluoromethylsulfonylamidophosphoric acid CF₃SO₂NHP(O)·(OEt)₂. The latter was also prepared by alcoholysis of N-(trifluoromethanesulfonyl)trichlorophosphazene or of potassium salt of dichloroanhydride of N-trifluoromethylsulfonylamidophosphoric acid, or by the reaction of the salt CF₃SO₂NHNa with diethylchlorophosphate. Compound CF₃SO₂N=P(OEt)₃ does not rearrange into the isomeric diethyl ester of N-ethyl-N-(trifluoromethylsulfonyl)amidophosphoric acid CF₃SO₂N(Et)P(O)(OEt)₂, contrary to the statement in the literature on the easy rearrangement of phosphazenes RFSO₂N=P(OEt)₃ into amidates RFSO₂N(Et)P(O)(OEt)₂.     

The First [4+2]‐Coordinated Tetraorganolead Compound: Synthesis,Structure and Conversion into a Triorganolead Cation,a Benzoxaphosphaplumbole,and Diorganolead Dihalides

The syntheses and molecular structures, as determined by single‐crystal X‐ray diffraction analysis, of the first intramolecularly [4+2]‐coordinated tetraorganolead compound {4‐t‐Bu‐2, 6‐[P(O)(OEt)₂]₂C₆H₂}PbPh₃ ( 2 ) and the triphenyllead chloride adduct of the first intramolecularly coordinated benzoxaphosphaplumbole {[1(Pb), 3(P)‐Pb(Ph)₂OP(O)(OEt)‐5‐t‐Bu‐7‐P(O)(OEt)₂]C₆H₂·Ph₃PbCl} ( 3a ) are reported. The reaction of 2 with [Ph₃C]⁺ [PF₆]^— and p‐MeC₆H₄SO₃H, respectively, provides the triorganolead salts {4‐t‐Bu‐2, 6‐[P(O)(OEt)₂]₂C₆H₂}PbPh₂⁺X^— ( 4 , X = PF₆; 4a , X = p‐MeC₆H₄SO₃). Reaction of 2 with bromine and hydrogen chloride, respectively, gives the diorganolead dihalides {4‐t‐Bu‐2, 6‐[P(O)(OEt)₂]₂C₆H₂}PbPhX₂ ( 5 , X = Br; 6 , X = Cl).     

A novel access to the anionic permethylated fac-tripod ligand [C5Me5Co&P(O)(OEt)2&3]−, and its derived trinuclear and binuclear complexes

[C₅Me₅Co&P(O)(OEt)₂&₃]Co(II) was obtained in high yield from the reaction of C₅Me₅Li with Co(acac)₃ and diethylphosphite in a one-step synthesis. This provides high-yield synthetic routes to several decamethylated triple-decker sandwiches [C₅Me₅Co&P(O)(OEt)₂&M [M = Co(III) or Ti(IV)], and pentamethylated binuclear complexes [C₅Me₅Co&P(O)(OEt)₂&₃]M′L_n, &M′L_n = [Re(CO)₃]⁺, [VO(acac)]⁺ or [Ru(η-C₆Me₆)]²⁺&.     

Addition Reactions of Me3SiCN with Aldehydes Catalyzed by Aluminum Complexes Containing in their Coordination Sphere O,S, and N Ligands

The reaction of one equivalent of LAlH₂ ( 1 ; L=HC(CMeNAr)₂, Ar=2,6‐iPr₂C₆H₃, β‐diketiminate ligand) with two equivalents of 2‐mercapto‐4,6‐dimethylpyrimidine hydrate resulted in LAl[(μ‐S)(m‐C₄N₂H)(CH₂)₂]₂ ( 2 ) in good yield. Similarly, when N‐2‐pyridylsalicylideneamine, N‐(2,6‐diisopropylphenyl)salicylaldimine, and ethyl 3‐amino‐4,5,6,7‐tetrahydrobenzo[b]thiophene‐2‐carboxylate were used as starting materials, the corresponding products LAl[(μ‐O)(o‐C₆H₄)CN(C₅NH₄)]₂ ( 3 ), LAlH[(μ‐O)(o‐C₄H₄)CN(2,6‐iPr₂C₆H₃)] ( 4 ), and LAl[(μ‐NH)(o‐C₈SH₈)(COOC₂H₅)]₂ ( 5 ) were isolated. Compounds 2 – 5 were characterized by ¹H and ¹³C NMR spectroscopy as well as by single‐crystal X‐ray structural analysis. Surprisingly, compounds 2 – 5 exhibit good catalytic activity in addition reactions of aldehydes with trimethylsilyl cyanide (TMSCN).     

Nickel-mediated N–N bond formation and N2O liberation via nitrogen oxyanion reduction

The syntheses of (DIM)Ni(NO₃)₂ and (DIM)Ni(NO₂)₂, where DIM is a 1,4-diazadiene bidentate donor, are reported to enable testing of bis boryl reduced N-heterocycles for their ability to carry out stepwise deoxygenation of coordinated nitrate and nitrite, forming O(Bpin)₂. Single deoxygenation of (DIM)Ni(NO₂)₂ yields the tetrahedral complex (DIM)Ni(NO)(ONO), with a linear nitrosyl and κ¹-ONO. Further deoxygenation of (DIM)Ni(NO)(ONO) results in the formation of dimeric [(DIM)Ni(NO)]₂, where the dimer is linked through a Ni–Ni bond. The lost reduced nitrogen byproduct is shown to be N₂O, indicating N–N bond formation in the course of the reaction. Isotopic labelling studies establish that the N–N bond of N₂O is formed in a bimetallic Ni₂ intermediate and that the two nitrogen atoms of (DIM)Ni(NO)(ONO) become symmetry equivalent prior to N–N bond formation. The [(DIM)Ni(NO)]₂ dimer is susceptible to oxidation by AgX (X = NO₃⁻, NO₂⁻, and OTf⁻) as well as nitric oxide, the latter of which undergoes nitric oxide disproportionation to yield N₂O and (DIM)Ni(NO)(ONO). We show that the first step in the deoxygenation of (DIM)Ni(NO)(ONO) to liberate N₂O is outer sphere electron transfer, providing insight into the organic reductants employed for deoxygenation. Lastly, we show that at elevated temperatures, deoxygenation is accompanied by loss of DIM to form either pyrazine or bipyridine bridged polymers, with retention of a BpinO⁻ bridging ligand.

Deoxygenation of nitrogen oxyanions coordinated to nickel using reduced borylated heterocycles leads to N–N bond formation and N₂O liberation. The nickel dimer product facilitates NO disproportionation, leading to a synthetic cycle.     

The Er and Yb Complexes with Silicon-Containing Phosphates and Fluorine-Containing Phosphine Oxide: Synthesis,Spectra, and Films

Three new silicon- and fluorine-containing ligands, namely bis(dimethylamido)(3-triethoxysilylpropylamido)phosphate O=P(NMe₂)₂NHCH₂CH₂CH₂Si(OEt)₃, diphenyl(3-triethoxysilylpropylamido)phosphate O=P(OPh)₂NHCH₂CH₂CH₂Si(OEt)₃, and tris(3,3,3-trifluoropropyl)phosphine oxide O=P(CH₂CH₂CF₃)₃ are synthesized. The erbium and ytterbium complexes with amine, phosphate, and phosphine oxide ligands Ln(NH₂R)₃Cl₃, Ln[O=P(NMe₂)₂NHR]₃Cl₃, Ln[O=P(OPh)₂NHR]₃Cl₃ (R=CH₂CH₂CH₂Si(OEt)₃), Ln[O=P(OPh)₃]₃Cl₃, Ln[O=P(CH₂CH₂CF₃)₃]₃Cl₃ are produced and their electronic absorption spectra and photoluminescence spectra are studied. The silicon-containing compounds form transparent thermostable films on silicate glass or quartz surface.     

Silver(I) diethylphosphite — Bonding mode and phosphine co-ordination compounds — a31P NMR study

Summary Silver(I) complexes with the P/O ambidentate phosphito- and phosphinito-ligands are shown to adopt P-bonded structures in solution by means of³¹P n.m.r. spectroscopy.¹J(Ag, P) of AgP(O)(OEt)₂ represents the largest one bond silverphosphorus coupling constant reported so far. AgP(O)(OEt)₂ forms co-ordination complexes of the stoichiometry [Ag{P(O)(OEt)₂}(PBu ₃ ⁿ )_n], n=1, 2 or 3 which were characterized by³¹P n.m.r. spectroscopy.The nomenclature accords with that used in the review of Roundhillet al. ⁽¹⁾.     

Two new XP(O)[NHC(CH3)3]2 phosphoramidates,with X = (CH3)2N and [(CH3)3CNH]2P(O)(O)

In N,N′‐di‐tert‐butyl‐N′′,N′′‐dimethylphosphoric triamide, C₁₀H₂₆N₃OP, (I), and N,N′,N′′,N′′′‐tetra‐tert‐butoxybis(phosphonic diamide), C₁₆H₄₀N₄O₃P₂, (II), the extended structures are mediated by P(O)...(H—N)₂ interactions. The asymmetric unit of (I) consists of six independent molecules which aggregate through P(O)...(H—N)₂ hydrogen bonds, giving R₂¹(6) loops and forming two independent chains parallel to the a axis. Of the 12 independent tert‐butyl groups, five are disordered over two different positions with occupancies ranging from to . In the structure of (II), the asymmetric unit contains one molecule. P(O)...(H—N)₂ hydrogen bonds give S(6) and R₂²(8) rings, and the molecules form extended chains parallel to the c axis. The structures of (I) and (II), along with similar structures having (N)P(O)(NH)₂ and (NH)₂P(O)(O)P(O)(NH)₂ skeletons extracted from the Cambridge Structural Database, are used to compare hydrogen‐bond patterns in these families of phosphoramidates. The strengths of P(O)[...H—N]_x (x = 1, 2 or 3) hydrogen bonds are also analysed, using these compounds and previously reported structures with (N)₂P(O)(NH) and P(O)(NH)₃ fragments.     

N,N′-Diaryl-chlormethanphosphonsäurediamide – Darstellung und Reaktionsverhalten

Preparation and Behaviour of N,N′-Diaryl-chlormethane Phosphonic Acid Diamides Chloromethan-phosphonic acid diamides of the type ClCH₂-P(O)(NHAr)₂ (Ar = p-C₆H₄OCH₃, p-C₆H₄OC₂H₅, o- and p-C₆H₄CH₃) can be prepared easily from ClCH₂P(O)Cl₂ and primary aromatic amines. These compounds yield with alcoholic potassium hydroxide solution the corresponding ethers and the reactions with secondary aliphatic amines or cyclohexylamin and n-propylamin, n-butylamin, respectively, give α-aminomethyl phosphonic acid diamides. The structure of ClCH₂? P(O)(NHAr)₂, ROCH₂? P(O)(NHAr)₂, R₂NCH₂? P(O)(NHAr)₂, and RHNCH₂? P(O)(NHAr)₂ is discussed on the basis of their infrared spectra and ¹H-nmr data.     

Triangular Ni2Ln and Ni2Y complexes derived from di-2-pyridyl ketone: Synthesis, structures and magnetic properties

The synthetic investigation of the Ni^II/M(NO₃)₃·6H₂O/di-2-pyridyl ketone [(py)₂CO] tertiary reaction system in EtOH has yielded triangular Ni₂M cationic complexes (M = lanthanide, Y). The reaction between Ln(NO₃)₃·6H₂O, Ni(ClO₄)₂·6H₂O, (py)₂CO and base (1:3:3:3) in EtOH under gentle heating gave the isostructural complexes [Ni₂Ln{(py)₂C(OEt)(O)}₃{(py)₂C(OH)(O)}(NO₃)(H₂O)](ClO₄)₂ (Ln = Gd, 2; Ln = Tb, 3) in high yields. The ligands (py)₂C(OEt)(O)⁻ and (py)₂C(OH)(O)⁻ are the monoanions of the hemiketal and gem-diol derivatives of (py)₂CO, respectively, formed in situ in the presence of the metal ions. The cations of 2 and 3 consist of one 8-coordinate Ln^III and two distorted octahedral Ni^II atoms in an essentially isosceles, triangular arrangement capped by a central μ₃-Ο⁻ atom of the unique 3.3011 (Harris notation) (py)₂C(OH)(O)⁻ ligand. Each metal-metal edge is bridged by the deprotonated O atom of one 2.2011 (py)₂C(OEt)(O)⁻ ligand. The isostructural complexes [Ni₂M{(py)₂C(OEt)(O)}₄(NO₃)(H₂O)]₂[M(NO₃)₅](ClO₄)₂ (M = Y, 4 ; M = Tb, 5 ; M = Dy, 6) were prepared by the 1:1 reaction of the mononuclear “metalloligand” [Ni(O₂CMe){(py)₂CO}{(py)₂C(OH)₂}](ClO₄) (1) and M(NO₃)₃·6H₂O in EtOH under mild heating in moderate to good yields. The structures of the dications of 4-6 are similar to those in 2 and 3, the only difference being the replacement of the unique 3.3011 (py)₂C(OH)(O)⁻ ligand of the latter by one 3.3011 (py)₂C(OEt)(O)⁻ group in the former. The Y^III, Tb^III and Dy^III atoms in [M(NO₃)₅]²⁻ are coordinated by five bidentate chelating nitrato groups. Characteristic IR bands of the complexes are discussed in terms of the known structures and the coordination modes of the ligands. Variable temperature, solid-state direct current magnetic susceptibility and magnetization studies were carried out on dried samples of 2-4. The data indicate ferromagnetic Ni?Ni and Ni?Gd exchange interactions, and an S_T = 11/2 ground state for 2. Complex 3 is characterized by a high-spin ground state while the ferromagnetic Ni?Ni interaction for 2 is independently supported by the study of 4. No out-of-phase, alternating current susceptibility signals have been detected for 3 that would be indicative of SMM behavior.     

Reaction of the Pincer‐type Ligand {2, 6‐[P(O)(OEt)2]2‐4‐tert‐Bu‐C6H2}— with [Ph3C]+[PF6]—. Unprecedented Rearrangement and Carbon‐Carbon Bond Formation

The reaction of the organolithium derivative {2, 6‐[P(O)(OEt)₂]₂‐4‐tert‐Bu‐C₆H₂}Li ( 1 ‐Li) with [Ph₃C]⁺[PF₆]^— gave the substituted biphenyl derivative 4‐[(C₆H₅)₂CH]‐4′‐[tert‐Bu]‐2′, 6′‐[P(O)(OEt)₂]₂‐1, 1′‐biphenyl ( 5 ) which was characterized by ¹H, ¹³C and ³¹P NMR spectroscopy and single crystal X‐ray analysis. Ab initio MO‐calculations reveal the intramolecular O···C distances in 5 of 2.952(4) and 2.988(5)Å being shorter than the sum of the van der Waals radii of oxygen and carbon to be the result of crystal packing effects. Also reported are the synthesis and structure of the bromine‐substituted derivative {2, 6‐[P(O)(OEt)₂]₂‐4‐tert‐Bu]C₆H₂}Br ( 9 ) and the structure of the protonated ligand 5‐tert‐Bu‐1, 3‐[P(O)(OEt)₂]₂C₆H₃ ( 1 ‐H). The structures of 1 ‐H, 5 , and 9 are compared with those of related metal‐substituted derivatives.     

Solid state and solution study of some phosphoramidate derivatives containing the P(O)NHC(O) bifunctional group: Crystal structures of CCl2HC(O)NHP(O)(NCH3(CH2C6H5))2, p-ClC6H4C(O)NHP(O)(NCH3(CH2C6H5))2, CCl2HC(O)NHP(O)(N(CH2C6H5)2)2 and p-BrC6H4C(O)NHP(O)(N(CH2C6H5)2)2

Synthetic methods for several novel phosphoramidate compounds containing the P(O)NHC(O) bifunctional group were developed. These compounds with the general formula R₁C(O)NHP(O)(N(R₂)(CH₂C₆H₅))₂, where R₁ = CCl₂H, p-ClC₆H₄, p-BrC₆H₄, o-FC₆H₄ and R₂ = hydrogen, methyl, benzyl, were characterized by several spectroscopic methods and analytical techniques. The effects of phosphorus substituents on the rotation rate around the P–N_amine bond were also investigated. ¹H NMR study of the synthesized compounds demonstrated that the presence of bulky groups attached to the phosphorus center and electron withdrawing groups in the amide moiety lead to large chemical-shift non-equivalence (Δδ_H) of diastereotopic methylene protons. The crystal structures of CCl₂HC(O)NHP(O)(NCH₃(CH₂C₆H₅))₂, p-ClC₆H₄C(O)NHP(O)(NCH₃(CH₂C₆H₅))₂, CCl₂HC(O)NHP(O)(N(CH₂C₆H₅)₂)₂ and p-BrC₆H₄C(O)NHP(O)(N(CH₂C₆H₅)₂)₂ were determined by X-ray crystallography using single crystals. The coordination around the phosphorus center in these compounds is best described as distorted tetrahedral and the P(O) and C(O) groups are anti with respect to each other. In the compound Br-C₆H₄C(O)NHP(O)(N(CH₂C₆H₅)₂)₂ (with two independent molecules in the unit cell), two conformers are connected to each other via two different N–H?O hydrogen bonds forming a non-centrosymmetric dimer. In the crystalline lattice of other compounds, the molecules form centrosymmetric dimers via pairs of same N–H?O hydrogen bonds. The structure of CCl₂HC(O)NHP(O)(N(CH₂C₆H₅)₂)₂ reveals an unusual intramolecular interaction between the oxygen of CO group and amine nitrogen.     

Synthesis of cis-[Ru(CO)2(S2X)2] [X = CNMe2, COEt, PPh2, P(OEt)2] and Molecular Structure of [Ru(CO){η2-S2P(OEt)2}{μ,η1,η2-S2P(OEt)2}]2

Two routes to 1,1-dithiolate complexes cis-[Ru(CO)₂(S₂X)₂] [X = NMe₂, OEt, PPh₂, P(OEt)₂] are presented. From the reaction of NH₄S₂P(OEt)₂ with the ruthenium(II) complex generated upon reduction of RuCl₃.3H₂O by CO in 2-methoxyethanol, along with the expected mononuclear product, cis-[Ru(CO)₂{η²-S₂P(OEt)₂}₂], binuclear [Ru(CO){η²-S₂P(OEt)₂} {μ,η¹,η²-S₂P(OEt)₂}]₂ was also produced. The latter has been crystallographically characterized and shows a trans-arrangement of carbonyls and cis-arrangement of terminal and bridging dithiolate ligands.     

Interactions des alcynes avec les complexes carbéniques du tungstène portant une double liaison carbone— carbone: Accès aux dérivés bicyclo[4,1,0] heptaniques par insertion-cyclopropanation

Treatment of VO(acac)₂ with the facial-tridentate organometallic ligand [η-CpCo{P(O)(OEt)₂}₃]^? affords a new binuclear compound [η-CpCo{P(O)(OEt)₂}₃VO(acac)] (I). This compound undergoes protonation with HPF₆ in the presence of 1,10-phenanthroline (phen), or 2,2′-bipyridyl (bipy), to yield binuclear cationic derivatives [η-CpCo{P(O)(OEt)₂}₃VO(phen))]⁺PF₆^? (II), and [η-CpCo{P(O)(OEth)₂}₃VO(bipy)]⁺PF₆^? (III). The X-ray crystal structure determination and full characterization of I has been performed. The catalytic oxygenation and oxygen transfer to 3,5-di-t-butylcatechol in the presence of I, II⁺, or III⁺ complexes is reported.     

Synthese linearer und verzweigter Phosphazene aus N-silylierten Phosphorylamiden

Synthesis of Lineary and Branched Phosphazenes from N-silylated Phosphoryl Amides The use of N-silylated phosphoryl amides in the reaction with PCl₅ favours the KIRSANOV reaction and reduces undesirable substitution reactions. However, silylated monoamides, X₂P(O)NHSiMe₃ (X = OEt, NEt₂), do not give the expected trichlorophosphazenes but the isomeric N-dichlorophosphoryl phosphazenes, Cl₂P(O)? N?PClX₂, which are also formed in the reaction of (EtO)₂P(O)NCl₂ with PCl₅. As the first phosphoryl-P, P-bis(trichlorophosphazene) (EtO)P(O)(N?PCl₃)₂ could be obtained in the reaction of PCl₅ with the silylated diamide (EtO)P(O)(NHSiMe₃)₂. Tris reactivity of silylated amides to P? Cl compounds decreases in the row PCl₅ > POCl₃ > CIP(O)(OEt)₂ > ClP(O)(NEt₂)₂. In the reaction with phosphoryl chlorides the preferred formation of compounds with P? NH? P bridges could not be observed.     

Regulation of electron donating ability to metal center: isolation and characterization of ruthenium carbonyl complexes with N,N- and/or N,O-donor polypyridyl ligands

Polypyridyl ruthenium(II) dicarbonyl complexes with an N,O- and/or N,N-donor ligand, [Ru(pic)(CO)₂Cl₂]⁻ (1), [Ru(bpy)(pic)(CO)₂]⁺ (2), [Ru(pic)₂(CO)₂] (3), and [Ru(bpy)₂(CO)₂]²⁺ (4) (pic=2-pyridylcarboxylato, bpy=2,2′-bipyridine) were prepared for comparison of the electron donor ability of these ligands to the ruthenium center. A carbonyl group of [Ru(L1)(L2)(CO)₂]ⁿ (L1, L2=bpy, pic) successively reacted with one and two equivalents of OH⁻ to form [Ru(L1)(L2)(CO)(C(O)OH)]ⁿ⁻¹ and [Ru(L1)(L2)(CO)(CO₂)]ⁿ⁻². These three complexes exist as equilbrium mixtures in aqueous solutions and the equilibrium constants were determined potentiometrically. Electrochemical reduction of 2 in CO₂-saturated CH₃CN–H₂O at −1.5 V selectively produced CO.