219 research outputs found
Bis(2,4,6-trimethylphenyl)zinc(II)
The title compound, [Zn(C9H11)2] or Mes2Zn (Mes = mesityl = 2,4,6-trimethylphenyl), crystallizes with a quarter of a molecule in the asymmetric unit. The ZnII atom is in a strictly linear environment with a Zn—C bond length of 1.951 (5) Å. Due to the imposed 2/m symmetry, both aromatic rings are coplanar. One of the methyl groups is disordered over two equally occupied positions
Tricarbonylbis(tricyclohexylphosphine-κP)ruthenium(0) toluene solvate
The title compound, [Ru(C18H33P)2(CO)3]·C7H8, shows a distorted trigonal-bipyramdial coordination around the central Ru atom, with the two phosphine ligands occupying the axial positions. Two toluene molecules per asymmetric unit with site-occupation factors of 0.5 are observed. One of them forces two of the CO ligands to enclose a wider C—Ru—C bond angle [127.5 (3)°] than in the solvent-free crystal structure of [Ru(PCy3)2(CO)3] (Cy is cyclohexyl)
A hydrogen-bridged adduct 3,4,6,7,8,9-hexahydro-2H-pyrimido[1,2-a]pyrimidin-1-ium [1,3-bis(tert-butyldimethylsilyloxy)-1,3-bis(pyridin-2-yl)propan-2-ylidene]nitronate acetonitrile monosolvate
The title compound, C7H14N3
+·C25H40N3O4Si2
−·CH3CN, was obtained by the reaction of 2-nitro-1,3-di(pyridin-2-yl)-1,3-di(tert-butyldimethylsilyloxy)propane with 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine. Two hydrogen bonds stabilize the Lewis acid/base pair of the nitronate and the guanidinium moiety with N⋯O distances of 2.772 (3) and 2.732 (3) Å. Both hydrogen atoms are more closely bound to the guanidinium [N—H distances of 0.83 (3) and 0.93 (3) Å] than to the nitronate moiety. The nitronate is double-bonded to the respective carbon with an N=C bond length of 1.316 (3) Å
Copper(II) hydrogenphosphate, CuHPO4
The title compound, CuHPO4, has been synthesized from a mixture of phosphoric acid and copper oxide. It has the same composition as MHPO4 (M = Ca, Ba, Pb, Sr or Sn), but adopts a rhombohedral structure with all atoms on general positions. The structure features distorted PO4 tetrahedra linked by copper, forming 12-membered rings. The CuII atom is coordinated by five O atoms in a distorted square-pyramidal manner. O—H⋯O hydrogen bonding leads to an additional stabilization of the structure
Synthesis and Structure of a New Bulky Hybrid Scorpionate/Cyclopentadienyl Ligand and its Lithium Complex
Abstract The reaction of 5‐(1‐adamantyl)‐3‐methyl‐1 H ‐pyrazole with dibromomethane yields a product mixture of bis(3‐adamantyl‐5‐methylpyrazolyl)methane (H 2 C(Pz Ad,Me ) 2 , 2 a ), (3‐adamantyl‐5‐methylpyrazolyl)‐(3‐methyl‐5‐adamantylpyrazolyl)methane ((H 2 C(Pz Ad,Me )(Pz Me,Ad ), 2 b ) and bis(3‐methyl‐5‐adamantylpyrazolyl)methane (H 2 C(Pz Me,Ad ) 2 , 2 c ). Lithiation of sterically congested H 2 C(Pz Ad,Me ) 2 ( 2 a ) and subsequent addition of diphenylfulvene yields lithium 1,1‐bis(3‐adamantyl‐5‐methylpyrazolyl)‐2,2‐diphenyl‐2‐ethyl‐ cyclo pentadienide, [(thf)Li{Cp−CPh 2 −CHPz Ad,Me }] ( 3 ) which is unable to form a thf adduct but can be hydrolyzed to H 5 C 5 −CPh 2 −CHPz Ad,Me ( 4 ). Adamantyl groups in 5‐position of bis(pyrazolyl)methane, i. e. 2 b and 2 c , prohibit formation of a fulvene adduct. For comparison reasons, [{H 5 C 5 −CPh 2 −CHPz Me2 }LiI] ( 1 b ) has been prepared via protolysis of (thf)lithium 1,1‐bis(3,5‐dimethylpyrazolyl)‐2,2‐diphenyl‐2‐ethyl‐ cyclo pentadienide, [(thf)Li{Cp−CPh 2 −CHPz Me2 }] ( 1 a ), in the presence of calcium iodide.imag
[(1-Azulenyl)methanethiolato-κS](1,4,8,12-tetraazacyclopentadecane-κ4 N)zinc(II) perchlorate
In the title compound, [Zn(C11H26N4)(C11H9S)]ClO4, the ZnII atom is five-coordinated by four N atoms from a neutral 1,4,8,12-tetraazacyclopentadecane aza-macrocycle molecule, and one S atom from an azulenylmethanethiolate ligand. Only monomers are found in the crystal. The coordination geometry can be described as trigonal bipyramidal, with the thiolate group in an equatorial position. The Zn—N and Zn—S distances are in the usual ranges for this type of complex
Synthesis, Structure, and Stability of Lithium Arylphosphanidyl‐diarylphosphane Oxide
The reaction of LiP(H)Tipp ( 2a ) and KP(H)Tipp ( 2b , Tipp = C 6 H 2 ‐2,4,6‐ i Pr 3 ), which are accessible via metalation of Tipp‐PH 2 ( 1 ), with bis(4‐ tert ‐butylphenyl)phosphinic chloride yields Tipp‐P=P(OM)Ar 2 [M = Li ( 3a ) and K ( 3b )]. These complexes show characteristic chemical 31 P shifts and large 1 J PP coupling constants. These compounds degrade with elimination of the phosphinidene Tipp‐P: and the alkali metal diarylphosphinites M–O–PAr 2 [M = Li ( 4a ) and K ( 4b )]. The phosphinidene forms secondary degradation products (like the meso and R,R/S,S ‐isomers of diphosphane Tipp‐P(H)–P(H)Tipp ( 5 ) via insertion into a P–H bond of newly formed Tipp‐PH 2 ), whereas the crystallization of [Tipp‐P=P(OLi)Ar 2 · LiOPAr 2 · LiCl · 2Et 2 O] 2 (i.e. [ 3a·4a· LiCl · 2Et 2 O] 2 ) succeeds from diethyl ether. The metathesis reactions of LiP(Si i Pr 3 )Tipp and LiP(Si i Pr 3 )Mes (Mes = C 6 H 2 ‐2,4,6‐Me 3 ) with Ar 2 P(O)Cl yield Ar*‐P=P(OSi i Pr 3 )Ar 2 (Ar* = Mes, Tipp) which degrade to Ar 2 POSi i Pr 3 and other secondary products.image John Wiley & Sons, Ltd
2-(Benzoylaminomethyl)pyridinium chloride
The title compound, C13H13N2O+·Cl−, (1), was obtained as a colorless crystalline by-product during the synthesis of N-(2-pyridylmethyl)benzoylamine (2). The C—O bond length of 1.231 (2) Å in the benzoyl unit of (1) is slightly elongated in comparison with isolated C=O double bonds as also observed for (2) [1.237 (2) Å]. The N—C bond length of 1.345 (2) Å in the benzoic acid amide unit indicates the formation of an allylic O—C—N system and is very similar to the N—C bond lengths [1.345 (2) Å] of the pyridyl group. A further delocalization of charge from this allylic system into the phenyl fragment does not occur, which can be deduced from a characterisitc C—C single bond length of 1.499 (2) Å between these fragments. A dimer is formed via N—H⋯Cl hydrogen bonds. The two rings make a dihedral angle of 105.0 (2)
One‐Step Synthesis and Schlenk‐Type Equilibrium of Cyclopentadienylmagnesium Bromides
Abstract In the in situ Grignard metalation method (iGMM), the addition of bromoethane to a suspension of magnesium turnings and cyclopentadienes [C 5 H 6 (HCp), C 5 H 5 ‐Si( i Pr) 3 (HCp TIPS )] in diethyl ether smoothly yields heteroleptic [(Et 2 O)Mg(Cp R )(μ‐Br)] 2 (Cp R =Cp ( 1 ), Cp TIPS ( 2 )). The Schlenk equilibrium of 2 in toluene leads to ligand exchange and formation of homoleptic [Mg(Cp R ) 2 ] ( 3 ) and [(Et 2 O)MgBr(μ‐Br)] 2 ( 4 ). Interfering solvation and aggregation as well as ligand redistribution equilibria hamper a quantitative elucidation of thermodynamic data for the Schlenk equilibrium of 2 in toluene. In ethereal solvents, mononuclear species [(Et 2 O) 2 Mg(Cp TIPS )Br] ( 2’ ), [(Et 2 O) n Mg(Cp TIPS ) 2 ] ( 3’ ), and [(Et 2 O) 2 MgBr 2 ] ( 4’ ) coexist. Larger coordination numbers can be realized with cyclic ethers like tetrahydropyran allowing crystallization of [(thp) 4 MgBr 2 ] ( 5 ). The interpretation of the temperature‐dependency of the Schlenk equilibrium constant in diethyl ether gives a reaction enthalpy ΔH and reaction entropy ΔS of −11.5 kJ mol −1 and 60 J mol −1 , respectively.Cyclopentadienylmagnesium bromides are accessible with high yields by a fast and smooth one‐pot synthesis. In hydrocarbons and in ethereal solvents a dissociative Schlenk equilibrium is operative interconverting heteroleptic compounds into homoleptic congeners. imag
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