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1.
The preparation of (borinato)(cyclobutadiene)cobalt complexes from the reactions of Co(C5H5BR)(1,5-C8H12) with acetylenes C2R′2 and of [C4(CH3)4]Co(CO)2I with Tl(C5H5BR) (R,R′ = CH3, C6H5) is described.In electrophilic substitution reactions Co(C5H5BCH3)[C4(CH3)4] (IVa) is more reactive than ferrocene. CF3CO2D effects H/D-exchange in the α-position of the borabenzene ring within a few minutes at ambient temperature and in the γ-position within less than four hours Friedel-Crafts acetylation with CH3COCl/AsCl3 in CH2Cl2 affords the 2-acetyl and the 2,6-diacetyl derivative of IVa. With the more active catalyst AlCl3, ring-member substitution is effected to give cations [Co(arene)C4(CH3)4]+ (arene = C6H5CH3, 2-CH3C6H4COCH3). Vilsmeier formylation gives the 2-formyl derivative of IVa. The acyl derivatives Co(2-R1CO-6-R2C5H3BCH3)[C4(CH3)4] (R1 = CH3, R2 = H, CH3CO and R1 = R2 = H) transform to the corresponding cations [Co(ortho-R1R2C6H4)C4(CH3)4]+ in superacidic media. The mechanistic relationship between acylation and ring-member substitution is discussed in detail.  相似文献   

2.
The complexes of trans-[Co(III)(R,CH3-dioxH)2(py)2]I2 (R = CH3, C2H5, n-C3H7 and n-C4H9) were investigated in solution by 1H and 13C NMR spectra and 13C spin-lattice relaxation time measurements. The 1H and 13C-resonances of the R = C2H5, n-C3H7 and n-C4H9) groups were shifted to higher field than those of the free ligands by the complexation; it was attributable to the ring current shielding due to the axial pyridine ligands of the complexes. 13C spin-lattice relaxation times were interpreted as due to movement of the axial pyridine ligands as if they twist around the CoN (pyridine nitrogen) bond axis and the above R groups were moving segmentally. These segmental movements allowed the R groups to approach closely toward the axial pyridine ring plane to experience the ring current shielding.  相似文献   

3.
5-C5(CH3)5]Co(O2C6H4) crystallizes in the orthorhombic space group Pnma with a 12.942(4), b 12.902(4), c 8.543(3) Å, V 1426(1) Å3, and Z = 4. Least-squares refinement of 1688 independent observed reflections, F(obs) ? 2.5σ(Fobs), gives RF 3.79 and RwF 3.72%. The cyclopentadienyl ring contains two short (1.412(3) Å) and three longer (〈av〉 1.430(4) Å) CC bond lenghts, consistent with a slight preference for diolefin bonding. The O2C6H4 fragment is best described as a catecholate with a CO bond distance of 1.338(3), and a CoO distance of 1.837(2) Å.  相似文献   

4.
Twentyfour complexes of the general formulae (R2SnL2 and R2(L)SnOSn(L)R2 (L = N-phthaloyl derivative of l-leucine, dl-alanine and l-phenylalanine; R = CH3, C5H5, n-C4H9) and n-C8H17) have been prepared by reacting ligand and dialkyltin(IV) oxide in 2/1 and 1/1 (ligand/metal) molar ratio. These complexes have been characterised by elemental analysis and structures assigned with the help of infrared, 1H NMR and 119Sn Mössbauer spectroscopy. These data support six-coordinated distorted octahedral structures with two alkyl groups in trans positions.  相似文献   

5.
From measurements of the heats of iodination of CH3Mn(CO)5 and CH3Re(CO)5 at elevated temperatures using the ‘drop’ microcalorimeter method, values were determined for the standard enthalpies of formation at 25° of the crystalline compounds: ΔHof[CH3Mn(CO)5, c] = ?189.0 ± 2 kcal mol?1 (?790.8 ± 8 kJ mol?1), ΔHof[Ch3Re(CO)5,c] = ?198.0 ± kcal mol?1 (?828.4 ± 8 kJ mo?1). In conjunction with available enthalpies of sublimation, and with literature values for the dissociation energies of MnMn and ReRe bonds in Mn2(CO)10 and Re2(CO)10, values are derived for the dissociation energies: D(CH3Mn(CO)5) = 27.9 ± 2.3 or 30.9 ± 2.3 kcal mol?1 and D(CH3Re(CO)5) = 53.2 ± 2.5 kcal mol?1. In general, irrespective of the value accepted for D(MM) in M2(CO)10, the present results require that, D(CH3Mn) = 12D(MnMn) + 18.5 kcal mol?1 and D(CH3Re) = 12D(ReRe) + 30.8 kcal mol?1.  相似文献   

6.
The synthesis of a new class of two-dimensional triazole compounds is described, including the crystal structure of [Co(NCS)2(btr)2]H2O [btr stands for 4,4′-bis-1,2,4-triazole (C4H4N6)]. Crystals are monoclinic, space group C2/c, a = 11.159(1) Å, b = 13.047(4) Å, c = 12.993(3) Å, β = 91.81(2)°, Z = 4. The structure has been solved by Fourier and direct methods and refined by full-matrix least squares to R = 0.0229, Rw = 0.0283. The structure consists of layers of six-coordinated cobalt atoms, each having two trans-oriented N-bonded thiocyanate groups [CoNCS 2.098(2) Å] and linked together in the equatorial plane by single bridges of btr to a two-dimensional network. The btr ligand coordinates through its N(1) and N(1′) atoms [CoN 2.128(1) and 2.142(1) Å]. The intralayer CoCo distance is 9.207(2) Å, and the inter-layer CoCo distance is 8.584(1) Å. The magnetic susceptibilities of the compound and of the isostructural nickel and iron compounds are discussed. The iron compound exhibits a high-spin-low-spin crossover at liquid-nitrogen temperatures, as shown by magnetic susceptibility.  相似文献   

7.
Bis(fluorbenzoyloxy)methyl phosphane oxides CH3P(O)[OC(O)R]2 [R = C6H42F (1), C6H43F (2), C6H44F (3), C6H32,6F2 (4), C6H2,3,5,6F4 (5)] were prepared by treating silver salts of carboxylic acids AgOC(O)R with CH3P(O)C?2 (IR-, 1H-, 19?F-and 31P{1H}-NMR-data). The mixed anhydrides 1–5 show unusual thermal stability at room temperature. Stability against hydrolysis decreases with increasing number of fluorine-atoms. The reaction of R′P(O)C?2 [R′ = CH3, C6H5, (CH3)3C] with MIOC(O)RF [RF = CF3, C2F5, C6F5; MI = AgI, NaI T?I] was investigated.  相似文献   

8.
Two novel assembling systems 3 and 4, with the structures of C6F5CF2?H+N(Me)2CH2CH2(Me2)N+H?CF2C6F5 and C6F5CF2I?N(Me)2CH2CH2(Me)2N?ICF2C6F5, respectively, have been generated from the solution of heptafluorobenzyl iodide 1 and N,N,N,N-tetramethylethylenediamine 2 in dichloromethane. Their structures have been characterized by X-ray diffraction analysis, NMR and IR spectroscopy. Intermolecular N?I halogen bond and F?H hydrogen bond are revealed to be the driving forces for their formation.  相似文献   

9.
We report two methods for preparing N-arylammonio, N-pyridyl and N-arylamino dodecaborates: heating of the tetrabutylammonium salt of dodecahydro-closo-dodecaborate(2-) with aryl and pyridyl amines, or nucleophilic attack of [closo-B12H11NH2]2− on a strongly deactivated aromatic system. With aryl amines we obtained [1-closo-B12H11N(R1)2C6H5] (R1 = H, CH3). With 4-(dimethylamino)pyridine, [1-closo-(B12H11NC5H4)-4-N(CH3)2], with a bond between the boron and the pyridinium nitrogen, was obtained. A presumable mechanism for this kind of reactions is reported. By nucleophilic substitution, two products, [1-closo-(B12H11NHC6H3)-3,4-(CN)2]2− and [1-closo-(B12H11NHC6H2)-2-(NO2)-4,5-(CN)2]2−, were formed with 4-nitrophthalonitrile and 1-chloro-2,4-dinitrobenzene gave [1-closo-(B12H11NHC6H3)-2,4-(NO2)2]2−. For [1-closo-B12H11N(CH3)2C6H5] and [1-closo-(B12H11NHC6H3)-2,4-(NO2)2]2− single crystal X-ray structures were obtained.  相似文献   

10.
The reaction of N,N′-dimethyloxamide with trialkyl derivatives of aluminium, gallium, and indium yields bis(dialkylmetal) compounds of structural formula (R2M)2[O2C2(NCH3)2] (M = Al, Ga, In; and R = CH3, C2H5). The M2O2C2N2 skeleton of these monomeric products forms an almost planar system of two fused five-membered rings, with S2 symmetry. For the dimethylgallium and dimethylindium derivatives, 1H and 13C NMR spectra show the presence of two conformational isomers which differ in the orientation of the N-methyl relative to the two metal-bound CH3 groups.  相似文献   

11.
This study describes a simple and efficient procedure to synthesize a novel series of fourteen 4-substituted N-(5-pyridinyl-1H-1,2,4-triazol-3-yl)-6-(trifluoromethyl)pyrimidin-2-amines, where the 4-substituents are H, CH3, C6H5, 4-FC6H4, 4-CH3C6H4, 4-CH3OC6H4 and 2-Furyl; from the cyclocondensation reaction of N-[5-(pyridinyl)-1H-1,2,4-triazol-3-yl]guanidines with 4-alkoxy-4-alkyl(aryl/heteroaryl)-1,1,1-trifluoroalk-3-en-2-ones. The reactions were carried out in ethanol under reflux for 18 h and led to 40-68% yields. N-(Pyridyl-triazolyl)guanidine precursors were further obtained from reactions of cyanoguanidine with nicotinic or isonicotinic acid hydrazides and the halogenated enones from trifluoroacetylation of enolethers or acetals.  相似文献   

12.
The reaction of n-butyllithium chelated to N,N,N′,N′-tetramethylethylenediamine (TMEDA) with acenaphthene results in 1,2-hydrogen abstraction to give the dilithio complex of acenaphthylene, [Li(CH3)2N(CH2)2N(CH3)2]2[C12H8]. This compound was isolated as a crystalline product and characterized by single crystal X-ray crystallography. [Li(CH3)2N(CH2)2N(CH3)2]2[C12H8] crystallizes with a unit cell of a = 23.164(10), b = 25.609(10) and c = 8.495(6) Å in the orthorhombice space group Fdd2. The calculated density is 1.04 g cm?3 for 8 molecules per unit cell. The observed density is 1.03(4) g cm?3. 1412 unique reflections were measured on a full circle X-ray diffractometer. The light atom, acentric structure was solved by the symbolic addition technique and refined by full matrix least squares to R1 = 0.058 and R2 = 0.056.The acenaphthylene fragment is nearly planar. The effect of charge transfer is evidenced in the short C(3)C(4) bond distance of 1.30(3) Å and the lengthening of the C(1)C(2) bond length from the localized olefinic bond distance of 1.34 to 1.42(2) Å. The two LiTMEDA fragments are coordinated to both sides of the five membered carbon atom ring of the acenaphthylene group.  相似文献   

13.
The enthalpy of the reaction: Pt(PPh3)2(CH2CH2)(cryst.) + CS2(g) → Pt(PPh3)2(CS2)(cryst.) + CH2CH2(g) has been determined as ΔH = ? 4.40 ± 2.2 kJ mol?1 from solution calorimetry, and the bond dissociation energy D(PtCS2) shown to be slightly greater than D(PtC2H4).  相似文献   

14.
Irradiation of solutions of n5-C5H5W(CO)3R (R  CH3n1-CH2C6H5) in cyclohexane at ca. 310490 nm leads to the formation of [n5-C5H5W(CO)3]2 and methane and of n5-C5H5W5(CO)2(n3-CH2C6H5) and some [n5-C5H5W(CO)3]2, respectively. When the irradiation is carried out in the presence of excess P(C6H5)3, the photoproducts are n5-C5H5W(CO)2[P(C6H5)3]CH3 (R  CH3) and n5-C5H5W(CO)2(n3-CH2C6H5) and trace [n5-C5H5W(CO)3]2 (R  n1-CH2C6H5). Photolysis of the n5-C5H5W(CO)3R in the presence of benzyl chloride affords n5-C5H5W(CO)3Cl (R  CH3) and both n5-C5H5W(CO)2(n3-CH2C2H5) and n5-C5H5W(CO)3Cl (R  n1-CH2C6H5), the relative amounts of the latter products depending on the quantity of added C6H5CH2Cl. Irradiation of n5-C5H5W(CO)3-CH3 in the presence of both P(C6h5)3 and C6H5CH2Cl affords n5-C5H5W(CO)2-[P(C6H5)3]CH3, but no n5-C5H5W(CO)3Cl. It is proposed that the primary photo-reaction in these transformations is dissociation of a CO group from n5-C5H5W-(CO)3R to generate n5-C5H5W(CO)2R, which can either combine with L to form a stable 18 electron complex, n5-C5H5W(CO)2(L)R (L  CO, P(C5H5)3; LR  n3-CH2C6H5), or lose the group R in a competing, apparently slower step. This proposal receives support from the observation that, light intensifies being equal, n5-C5H5W(CO)3CH3 undergoes a considerably faster photoconversion to [n5-C5H5W(CO)3]2 under argon than under carbon monoxide.  相似文献   

15.
N-(2-Hydroxybenzyl)aminopyridines (Li) react with Cu(II) and Pd(II) ions to form complexes in the compositions Cu(Li)2(CH3COO)2 · nH2O (n = 0, 2, 4), Pd(Li)2Cl2 · nC2H5OH (n = 0, 2) and Pd(L2)2Cl2 · 2H2O. In the complexes, the ligands are neutral and monodentate which coordinate through pyridinic nitrogen. Crystal data of the complexes obtained from 2-amino pyridine derivative have pointed such a coordinating route and comparison of the spectral data suggests the validity of similar complexation modes of other analog ligands. Cu(II) complex of N-(2-hydroxybenzyl)-2-aminopyridine (L1), [Cu(L1)2(CH3COO)2] has slightly distorted square planar cis-mononuclear structure which is built by two oxygen atoms of two monodentate carboxylic groups disposed in cis-position and two nitrogen atoms of two pyridine rings. The remaining two oxygen atoms of two carboxylic groups form two Cu and H bridges containing cycles which joint at same four coordinated copper(II) ion. IR and electronic spectral data and the magnetic moments as well as the thermogravimetric analyses also specify on mononuclear octahedric structure of complexes [Cu(L2)2(CH3COO)2 · 2H2O] and [Cu(L3)2(CH3COO)2 · 4H2O] where L2 and L3 are N-(2-hydroxybenzyl)-2- or 3-aminopyridines, respectively.  相似文献   

16.
Organotin and organolead derivatives of N-(2,4-dinitrophenyl)glycine (HDNG), R3MDNG (M = Sn, Pb; R = CH3, C6H5) and (C6H5)2Pb(DNG)2, have been prepared from R3MOH or [(C6H5)2PbO]n and HDNG, respectively. (CH3)3PbDNG was also obtained from (CH3)3PbBr and TlDNG. According to spectroscopic data R3M groups in R3MDNG are essentially planar and are bridged by bidentate carboxylate groups of DNG. NH does not coordinate to M. Penta-coordination is also indicated by Mössbauer data of R3SnDNG. Also for (C6H5)2Pb(DNG)2 a chain structure but with hexacoordination of Pb is proposed. The compounds are monomeric in solution.  相似文献   

17.
The syntheses and properties of the titanium(III) complexes Cp2Tir · R′CN (R = C6H5, o-, m-, p-CH3C6H4, CH2C6H5, C6F5, Cl; R′ = CH3, t-C4H9, C6H5, o-CH3C6H4, 2,6-(CH3)2C6H3) are described. In the complexes the nitrogen atom of the cyanide ligands is coordinated to the metal. The thermal stabilities of the complexes depend markedly on R and R′; on heating they undergo a novel reaction in which two cyanide ligands are coupled by formation of a CC bond, while the metal is oxidized to titanium(IV).  相似文献   

18.
Summary Pyridinium ylide complexes of methylcobaloxime were synthesized by the treatment of an ylide with Co(Hdmg)2 Me(SMe2). The crystal structure of one of the complexes, [Co(Hdmg)2Me C5H5NCHCOPh]C6H6 has been determined by x-ray diffraction techniques. The crystals are monoclinic, space group P21/c, witha = 10.456(5),b = 11.079(4),c = 24.58(1) Å, = 99.58(6), V = 2808 Å3, Z = 4. The Co-C (ylide) bond distance is 2.18 Å and Co-C(methyl) 2.04 Å. C(ylide)-Co-C(methyl) bond angle is 174.9°. The crystal, i.r. and1H n.m.r. data suggest that thetrans-influence of the ylide ligands is larger than that of py, Melm, OH2 or PPh3.  相似文献   

19.
The complexes trans-dichloro[R(CH3)C*HCH=CH2](pyridine)platinum-(II), R = C2H5, i-C3H7, t-C4H9, have been prepared and their 1H NMR and CD spectra investigated. The two diastereomers formed in the complexation of the chiral α-olefin to PtII are present in different concentrations in solution, the diastereomer of opposite absolute configuration at the two chiral centres being the prevailing one. The extent of stereoselectivity, evaluated both by NMR and CD, varies from 32% to 75% by changing the bulkiness of the R group. The preferred conformation of the two diastereomers for each complex has been established by NMR, taking into account the deshielding effect on the protons bound to saturated carbon atoms as well as J(HH) and J(PtH) coupling constants.  相似文献   

20.
C5H5Co(PMe3)CS2 (IV) is formed in practically quantitative yield in the reaction of C5H5Co(PMe3)2 (I) or the heterobinuclear complex C5H5(PMe3)Co(CO)2Mn(CO)C5H4Me (III) with CS2. The crystal structure shows that the carbon disulfide bonds as a dihapto ligand through the carbon and one sulfur atom (S(2)) (CoC = 1.89, CoS(2) = 2.24 Å, S(2)CS(1) = 141.2°). The two CS bond lengths in IV (CS(2) = 1.68, CS(1) =1.60 Å) are greater than in free CS2 (1.554Å) which is in agreement with the strong π-acceptor character of h2-CS2 as shown in the spectroscopic data. IV reacts with Cr(CO)5THF and C5H5Mn(CO)2THF to give the complexes C5H5(PMe3)Co(SCS)Cr(CO)5 (V) and C5H5(PMe3)Co(SCS)Mn(CO)2C5H5 (VI) respectively, in which the sulfur atom S(1) that is not bound to cobalt coordinates to the 16-electron fragments Cr(CO)5 and Mn(CO)2C5H5. The spectroscopic data of IV, V and VI are discussed.  相似文献   

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