Sulfur-assisted chloride and triphenylphosphine dissociation of palladium(II) complex [Pd(PPh3)2(η1-SCNMe2)(Cl)]. X-ray structures of [Pd(PPh3)2(η1-SCNMe2)(Cl)], [Pd(PPh3)(Cl)]2(μ,η2-SCNMe2)2, and [Pd(PPh3)2(η2-SCNMe2)][PF6]

Treatment of Pd(PPh₃)₄ with Me₂NC(S)Cl in dichloromethane at −20 °C produces the complex [Pd(PPh₃)₂(η¹-SCNMe₂)(Cl)], 2. Variable temperature ¹H and ³¹P{H} NMR experiments of complex 2 shows the dissociation of either the chloride or the triphenylphosphine ligand to form complex [Pd(PPh₃)₂(η²-SCNMe₂)][Cl], 3 or the dipalladium complex [Pd(PPh₃)Cl]₂(μ,η²-SCNMe₂)₂, 4. The reaction of complex 2 with NaPF₆ affords complex [Pd(PPh₃)₂(η²-SCNMe₂)][PF₆], 5. Complexes 2, 4, and 5 are characterized by X-ray diffraction analyses.     

Phosphorus–carbon bond cleavage of Ph2PCH2PPh2 at a triruthenium center: synthesis and structural characterization of [Ru3(μ-CO)(CO)6(μ-PPh2)2(μ3-CH2PPh)]

The reaction of Ph₂PH with [Ru₃(CO)₁₀(μ-dppm)] (1) at 98°C gave [Ru₃(μ-CO)(CO)₆(μ-PPh₂)₂(μ₃-CH₂PPh)] (7) in 20% yield. Compound 7 was characterized by elemental analysis, ¹H and ³¹P{¹H} NMR and mass spectroscopic data and also by a single crystal structure determination. The compound is shown to consist of a triruthenium cluster with an unusual example of a triply bridging CH₂PPh ligand and two doubly bridging PPh₂ ligands.     

[Re(NBH2SBH3)(Me2PhP)(Et2dtc)]2 — a novel rhenium dimer with the unusual bridging (NBH2SBH3)4− ligand

The title compound is formed during the reaction of [ReN(Me₂PhP)(Et₂dtc)₂] (Me₂PhP=dimethylphenylphosphine, Et₂dtc⁻=diethyldithiocarbamate) with excess BH₃ in tetrahydrofurane. Two Re^V atoms are linked by two (NBH₂SBH₃)⁴⁻ units which act as three-dentate ligands via N, S and H forming an eight-membered metallacycle with additional coordination of an hydrido H atom trans to the nitrogen atom. The ReN multiple bond length is 1.70(1) Å which is only slightly longer than in the starting compound [ReN(Me₂PhP)(Et₂dtc)₂] (1.666(6) Å).     

A new lead(II) inorganic–organic hybrid of the P,P′-diphenylmethylene-diphosphinate ligand: synthesis and X-ray characterization of the [Pb(CH2(P(Ph)O2)2)] complex

By reaction of lead(II) nitrate with P,P^′-diphenylmethylenediphosphinic acid in water solution a new inorganic–organic hybrid of formula [Pb(CH₂(P(Ph)O₂)₂)] has been synthesized and structurally characterized. The complex displays a polymeric columnar structure, the column being formed by two intersecting sinusoidal ribbons of lead(II) ions bridged by bifunctional phosphinate ligands. The intersections of the ribbons are constituted by dimeric units of pentacoordinated lead(II) ions.     

Rapid phosphorus–nitrogen bond cleavage in bis(diphenylphosphino)amine. Synthesis,X-ray structure and electrochemical characterization of [Ni2(μ2-Ph2P)(μ2-Ph2PNHPPh)2(CNR)2]X,R=Me,n-Bu,Xylyl; X=Cl,I, BPh4 binuclear Ni(I) complexes

Ni(II) reacts with Ni(0) complexes in toluene solution to yield diamagnetic phosphido-bridging Ni(I)–Ni(I) complexes of the type Ni₂(μ²-PPh₂)(CNR)₂(μ²-dppa)₂. The great thermodynamic stability of these complexes is discussed on the light of their electrochemical properties. The X-ray crystal structure of the complexes Ni₂(μ²-PPh₂)(CNR)₂(μ²-dppa)₂, R=n-Bu, Xylyl is also presented.     

Reactivity of [WCl(SnCl3)(CO)3(NCMe)2] towards tBuCCH.: X-ray crystal structure of [WCl(CO)(tBuCCH)(NCMe)(PPh3)2]2[SnCl6]

In the reaction of [WCl(SnCl₃)(CO)₃(NCMe)₂] with tert-butylacetylene the very labile bis(alkyne) complex [WCl(SnCl₃)(CO)(^tBuCCH)₂(NCMe)] has been observed as the major product by means of IR and NMR spectroscopy. The latter compound in reaction with two equivalents of PPh₃ in CH₂Cl₂ solution gives very poorly soluble purple crystals of the tungsten(II) cationic complex. The crystal structure of this compound consists of the discrete [SnCl₆]²⁻ anion, two independent [WCl(CO)(^tBuCCH)(NCMe)(PPh₃)₂]⁺ cations and four MeCN (solvent) molecules. This is the first crystallographically characterized cationic chlorocarbonyl complex of tungsten(II) containing a terminal alkyne as ligand.     

Hydrothermal synthesis of a novel microporous framework sustained by polycatenated [CuI2(ip)(4,4′-bipyridine)]n (ip = isophthalate) ladders

A novel ladder coordination polymer [Cu^I₂(ip)(4,4^′-bipyridine)] · 3.5H₂O (1) (ip=isophthalate) was prepared via redox reaction under hydrothermal conditions and characterized by single-crystal X-ray diffraction analysis. In the crystal structure of 1, each ring of the ladder is interlocked by two different, symmetry-related ladders, and the polycatenation of ladders forms a 3D network with rhombic channels clathrating water molecules.     

Synthesis of an osmafuran from photochemical hydrolysis of OsCl2(CHC(PPh3)C(O)-η2-CHCH2)(PPh3)2

The η²-alkene coordinated α,β-unsaturated ketone complex Os(CHC(PPh₃)C(O)-η²-CHCH₂)Cl₂(PPh₃)₂ (3) is very stable even at elevated temperature due to the strong steric hindrance effect of PPh₃ ligands. However, compound 3 in a chloroform solution can be almost quantitatively converted into the corresponding osmafuran [OsCl(CO)(PPh₃)₂(CHC(PPh₃)C(CH₃)O)]Cl (6) via hydrolysis of the η²-coordinated olefin under photochemical conditions. Osmafuran 6 has been characterized by single crystal X-ray diffraction analysis, NMR spectroscopy and elemental analysis data. The UV-induced reaction provides a new highly efficient method for preparation of osmafurans by hydrolysis of η²-α,β-unsaturated ketone complexes.     

Preparation of Ru(η3-2-alkenylallyl)(CO)Cl(PPh3)2 complexes via carbometallation of allenes with alkenyl ruthenium complexes

Alkenyl ruthenium complex, Ru(CHCHR)(Cl)(CO)(PPh₃)₂ 1, reacted with allenes 2 to give η³-allyl ruthenium complexes, Ru(η³-2-alkenylallyl)(Cl)(CO)(PPh₃)₂ 3, in good yields. The reaction depends on the structure of the alkenyl group. When R was phenyl or methoxycarbonyl group, the carbometallated complex 3 was yielded as a sole product. However, when R was butyl or trimethylsilyl group, besides the carbometallation product as main product, was obtained a small amount of 2-unsubstituted η³-allyl ruthenium complex which was formed via β-elimination of the alkenyl complex followed by the reaction with allene. Structure of 3 was determined by the X-ray crystal structure analysis.     

The first complex of the pentameric phosphazane macrocycle [{P(μ-NtBu)}2(μ-NH)]5 with a neutral molecular guest: Synthesis and structure of [{P(μ-NtBu)}2(μ-NH)]5(CH2Cl2)2

The reaction of [{P(μ-N^tBu)}₂(μ-NH)}₅I]⁻[Li(thf)₄]⁺([1 · I]⁻[Li(thf)₄]⁺) with NaOMe in CH₂Cl₂ gives the title compound [{P(μ-N^tBu)}₂(μ-NH)]₅(CH₂Cl₂)₂ [1 · (CH₂Cl₂)₂] the first adduct containing this type of macrocyclic phosph(III)azane host and a neutral guest.     

Synthesis and Structure of New Dimeric Cyclopentadienyl Titanium Fluorine–Oxygen Systems: [Cp*TiF(μ-F)(μ-OPOPh2)]2, [Cp*TiF(μ-F)(μ-OSO2-p-C6H4Me)]2 and [Cp*TiF2(μ-OMe)]2

The reactions of Cp*TiF₃ with Me₃SiOPOPh₂, Me₃SiOSO₂-p-C₆H₄Me, and Al(OMe)₃ resulted in the formation of the dimers [Cp*TiF(μ-F)(μ-OPOPh₂)]₂ 1 , [Cp*TiF(μ-F)(μ-OSO₂-p-C₆H₄Me)]₂ 2 , and [Cp*TiF₂(μ-OMe)]₂ 3 , respectively, in good yields. In contrast to the formation of 3 , Cp*TiF₃ reacts with Al(OH)₃ to afford the known tetramer [Cp*TiF(μ-O)]₄ 4 . The structures of 1–3 have been determined by X-ray crystallography; compounds 1 and 3 crystallize in the monoclinic space group P2₁/c and compound 2 in the monoclinic space group P2/n. Compound 1 is the first example of a dimeric Cp*-titanium phosphinate containing a fluorine ligand. The core of the dimeric structure of both 1 and 2 consists of two Ti atoms bridged by two fluorine atoms and two bidentate groups. In contrast, the dimeric structure of 3 consists of two Ti atoms bridged only by two methoxy groups. An equilibrium of isomers of 1 and 2 has been observed in solution by ¹H and ¹⁹F NMR. The ¹⁹F NMR spectra of 1–3 are discussed in detail.     

The preparation,structure and unusual substitution reactions of the cationic 2-butyne complex [WI(CO)(NCMe){P(OiPr)3}2(η2-MeC2Me)][BPh4]

Reaction of equimolar amounts of [WI₂(CO){P(OⁱPr)₃}₂(η²-MeC₂Me)] and Na[BPh₄] in acetonitrile at room temperature gave the crystallographically characterised complex [WI(CO)(NCMe){P(OⁱPr)₃}₂(η²-MeC₂Me)][BPh₄] (1). Complex 1 undergoes a series of substitution reactions, including the reaction of 1 with 1,10-phenanthroline at room temperature, to afford the unexpected structurally characterised product, [WI(CO){P(OⁱPr)₃}(1,10-phen)(η²-MeC₂Me)][BPh₄] (2) via displacement of one phosphite and the acetonitrile ligand.     

Reactions of benzophenone imine complex [Tp(NH═CPh2)(PPh3)Ru–Cl] with alkyne and dimerization of terminal alkynes in the presence of Et3N

Treatment of benzophenone imine complex [Tp(PPh₃)(NH═CPh₂)Ru–Cl] (1) {Tp═HB(pz)₃, pz = pyrazolyl} with 4-Ethynyltoluene in the presence of H₂O in distilled ethanol afforded the chelate alkenyl ketone complex [Tp(PPh₃)RuCCH₂(p-MeC₆H₄)═CHC(O)(p-MeC₆H₄)] (2). On the other hand, reaction of 1 with HC≡C(O)OR₁ in R₂OH produced the chelate vinyl ether complexes [Tp(PPh₃)Ru–C(OR₂)═CHC(O)OR₁] (3a, R₁ = Me, R₂ = Me; 3b, R₁ = Et, R₂ = Me; 3c, R₁ = Et, R₂ = Et; 3d, R₁ = Me, R₂ = Et), respectively. Preliminary results on the catalytic activity of 1 are also presented. Intriguingly, complex 1 is found to catalyze the dimerization of terminal alkynes HC≡CR (R = p-MeC₆H₄, C(O)OCH₃) in the presence of Et₃N to give eynes. The structures of 3c and 3d have been determined by X-ray diffraction analysis.     

Square-planar d8 metal push–pull dithiolene complexes: Synthesis and characterization of [Pd(Me2pipdt)(dmit)]

Experimental and theoretical results on the novel [Pd(Me₂pipdt)(dmit)] complex (1) based on the push Me₂pipdt (1,4-dimethyl-piperazine-3,2-dithione) and pull dmit (1,3-dithiolo-2-thione-4,5-dithiolato), show that an unbalanced electron distribution at the dithiolene core occurs. The presence of a solvatochromic absorption at low energy, shifted to higher frequency when compared to the corresponding nickel case, points out that these complexes are potential second-order non-linear chromophores, whose properties are tunable with the metal.     

Comparison of the structural properties of compounds containing the XSSX moiety (X = H,Me, R,Cl, Br,F, OR)

A comparison of the structural parameters of a wide variety of compounds containing the S–S bond is summarized.     

The solid state reaction between RhX(PPh3)3 and (η5-C5H4Me)W (CO)3X (X = Cl,Br, I)

Reaction between RhX(PPh₃)₃ (X = Cl, Br, I) and (η⁵-C₅H₄Me)W(CO)₃Y (Y = Cl, Br, I) occurs in both the solution and the solid state and leads to exchange of both CO/PPh₃ and X/Y between the two reactants.     

Keggin型多阴离子[XW_(12)O_(40)]~(n-)(X=Si,Ge,P,As)电子性质的密度泛函理论研究

采用密度泛函理论方法研究了Keggin型多阴离子[XW12O40]n-(X=Si,Ge,P,As)的电子性质,在几何优化基础上,分析杂原子对体系的几何结构,电子性质,氧化还原性质的影响。结果表明:杂原子对多阴离子的键长有影响,变化规律与杂原子半径递变一致;杂原子的电子性质影响多阴离子的氧化性,多阴离子的氧化能力随杂原子的电负性增大而提高;杂原子的核电荷数越大,该多阴离子的氧化性越强;多阴离子的酸强度与杂原子的电负性次序一致。     

Hydrothermal synthesis and crystal structure of a metal–organic coordination polymer with double-helical structure: [Fe(phen)(ipt)]n (ipt=isophthalate,phen=1,10-phenanthroline)

A novel metal–organic coordination polymer [Fe(phen)(ipt)]_n 1 has been hydrothermally synthesized and structurally characterized. Compound 1 exhibits a novel neutral cross double-helical structure composed of left-handed and right-handed helical chains.