Synthesis and Crystal Structure of 2,3-Diethoxycarbonyl-4-phenyl-5-morpholinyl Thiophene

1INTRoDUCTIONa-Thiocarbonylthioformamidesweresynthesizedin198o[l~2i,however,thereisnoreportofthesecompoundsconcerningtheirpropertiesandreactionactivitiest33.Accordingtotheirstructure,theyseemtohavereactionwithdienophi1es,likesubsti-tutedolefinicandacetylenicdienophilestoleadcorrespondingDiels-Alderproduct.xylene(15ml),diethylbutynedioicester(O.2g,1.2mmol)wasadded,themix-turewasrefluxedfor20h,thencooledtoroomtemperatureandconcentrated.Theresiduewaspurifiedbysilicagelcolumnusingacetone/petr…     

Crystal Structure of 4, 5-trans-2-Amino-1, 3, 3-tricyano-4, 5-di (4-chlorophenyl)cyclopentene. Ethanol. Monohydrate

1mTRODUCT10NSincethetimeKaganhasdem0nstratedasimplepreparationofsamariumdiio-didefromsamariummetaland1,2-diiodoethanet1),SmI2hasbeenwidelyusedinsyntheticreactionst23.Thereactivityofsamariumdiiodidetowardsvariousnitrogen-containingcomP0undshasalreadybeenexamined.Thereare,toourknowledge,noliteratureexamplesforthereductionofcyanogrouptoproduceaminowiththisreagent.Inthispaper,wediscussedthecrystalstructureofthetitlecomP0undsyn-thesizedbythereactionofsamariumdii0didereagentwithp-chloroben-zyli…     

咪唑桥连四氮大环双铜配合物合成和晶体结构

超氧化物歧化酶由于它能有效地消除毒性很大的O；自由基对正常细胞的侵害，防止细胞癌变与衰老·近年来日益受到重视·铜锌超氧化物歧化酶（CuZn－SOD）的活性中心具有独特的咪哩桥连的Cu口）、Zn（11）离子的结构，令人感兴趣的是用铜取代锌后而形成的四铜蛋白CllZCllZSOD仍具有催化活性［‘］．作为Cll。Cll。SOD活性中心的模拟物，一系列以咪哩桥连的双铜配合物被制备和研究＊．我们合成了以四氮大环为配体的咪哩桥连双铜配合物，以下报导此配合物的合成和晶体结构．1实验1．1配体、配合物的合成与单晶的制备1厂一二甲基4，4，71…     

Synthesis and Structure of 6-(4- Fluorobenzylamino)-3-methylthio-1,5- diphenyl-1H-pyrazolo[3,4-d]pyrimidin-4(5H)-one

1 INTRODUCTION It was reported that the pyrazolopyrimidinone derivatives play a very important role in the bio- chemistry of living cell. Many potential drugs[1～3] and agrochemicals[4, 5] have been modeled on the compound, and the study on derivatives …     

Synthesis and Crystal Structure of 2-Methoxy-benzoic Acid 2-Oxo-3-（2,4,6-trimethyl-phenyl）-1-oxa-spiro[4.4]non-3-en-4-yl Ester

The new title compound 2-methoxy-benzoic acid 2-oxo-3-(2,4,6-trimethyl-phenyl)-1-oxa-spiro[4.4]non-3-en-4-yl ester(3,C25H26O5) has been synthesized by the condensation reaction of 4-hydroxy-3-(2,4,6-trimethyl-phenyl)-1-oxa-spiro[4.4]non-3-en-2-one(2) with 2-methoxylben-zoyl chloride,and characterized by 1H NMR and MS spectra.Its crystal structure was determined by single-crystal X-ray diffraction.The crystal is of monoclinic,space group P21/c with a = 10.6945(7),b = 12.8176(7),c = 16.4223(10) ,β = 103.5665(17)o,V = 2188.3(2) 3,Z = 4,Dc = 1.234 g/cm3,F(000) = 864.000,μ = 0.085 mm-1,the final R = 0.0520 and wR = 0.1132 for 2732 observed reflections with I 2σ(I).In the crystal structure,the C(1)-C(2)(1.478 ) bond is significantly shorter than the normal single C-C bond(1.53 ),suggesting that the carbonyl group on C(1) has formed a conjugated system with a double bond on C(2) and C(12).     

Molecular structure of 1,5-diazabicyclo[3.1.0]hexane as determined by gas electron diffraction and quantum-chemical calculations

The equilibrium molecular structure and conformation of 1,5-diazabicyclo[3.1.0]hexane (DABH) has been studied by the gas-phase electron-diffraction method at 20 degrees C and quantum-chemical calculations. Three possible conformations of DABH were considered: boat, chair, and twist. According to the experimental and theoretical results, DABH exists exclusively as a boat conformation of C s symmetry at the temperature of the experiment. The MP2 calculations predict the stable chair and twist conformations to be 3.8 and 49.5 kcal mol(-1) above the boat form, respectively. The most important semi-experimental geometrical parameters of DABH (r(e), A and angle)e), deg) are (N1-N5) = 1.506(13), (N1-C6) = 1.442(2), (N1-C2) = 1.469(4), (C2-C3) = 1.524(7), (C6-N1-C2) = 114.8(8), (N5-N1-C2) = 107.7(4), (N1-C2-C3) = 106.5(9), and (C2-C3-C4) = 104.0(10). The natural bond orbital (NBO) analysis has shown that the most important stabilization factor in the boat conformation is the n(N) --> sigma*(C-C) anomeric effect. The geometry calculations and NBO analysis have been performed also for the bicyclohexane molecule.     

双(η~5-异丙基环戊二烯基)六羰基二钼的合成及分子结构

本文报道了(η~5-C_5H_4C_3H_7—i)_2Mo_2(CO)_6的合成及晶体结构。晶体属于三斜晶系,空间群P,晶胞参数a=7.548(2),b=8.662(1),c=8.888(1),a=91.11(1),β=106.43(1),γ=92.59(1)°,V=556.48,M_r=574.3,Z=1,D_x=1.714g/cm~3,μ(MoKα)=11.33cm~(-1),F(000)=286。最后偏离因子R=0.016。分子具有C_i对称性。分子中存在Mo—Mo单键,键长为3.222。异丙基的引入使得茂环与金属钼的键合加强。     

Synthesis, Characterization and Crystal Structure of [Co2Mo2(μ4-C2HPh)(μ-CO)4(CO)4(η5-C5H4C(O)Me)2]

The reaction of μ-alkyne-bridged dimolybdenum compound [Mo2(μ-C2HPh)(CO)4(η5-C5H4C(O)Me)2] 1 with Co2(CO)8 in refluxing toluene gave a new butterfly compound [Co2Mo2(μ4-C2HPh)(μ-CO)4(CO)4(η5-C5H4C(O)Me)2] 2 which was fully characterized by elemental analysis, IR, 1H NMR and X-ray single crystal diffraction techniques. 2 crystallized in monoclinic system, C30H20Co2Mo2O10, Mr=850.23, space group P21/a(#14), a=14.165(5), b=12.498(2), c=16.204(2)(A), β = 96.50(2)°, V = 2850(1)(A)3, Z = 4, Dc = 1.981 g cm-3, F(000)=1672, μ(MoKα)=20.41 cm-1, final R=0.030, Rw=0.039 for 4831 observable reflections with I>2σ(I). The structure contains a Co2Mo2 butterfly core, and each Mo-Co bond is spanned by an asymmetric semi-bridging carbonyl ligand.     

The structural characteristics of organozinc complexes incorporating N,N'-bidentate ligands

Dimethylzinc reacts with an excess of N-2-pyridylaniline 6 to give the homoleptic species, Zn[PhN(2-C(5)H(4)N)](2) 8. Single crystal X-ray diffraction reveals a solid-state dimer based on an 8-membered (NCNZn)(2) core motif. Zn[CyN(2-C(5)H(4)N)]Me (Cy =c-C(6)H(11)) 10, prepared by the combination of ZnMe(2) with the corresponding cyclohexyl-substituted pyridylamine, is also dimeric in the solid state but reveals a central (ZnN)(2) metallacycle. Employment of (p-Tol)NH(2-C(5)H(4)N)(p-Tol = 4-MeC(6)H(4)) 11 yielded the tris(zinc) adduct Zn(3)[(p-Tol)N(2-C(5)H(4)N)](4)Me(2) 12, which incorporates a central chiral molecule of 'Zn[(p-Tol)N(2-C(5)H(4)N)](2)' 12a, that bridges two 'Zn[(p-Tol)N(2-C(5)H(4)N)]Me' 12b units. A similar trimetallic structure is noted when the pyridylaniline substrate 11 is replaced with the bicyclic guanidine 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine (hppH), affording Zn(3)(hpp)(4)Me(2) 13. Spectroscopic studies point to retention of the solid-state structure of in hydrocarbon solution. Reaction of 13 with dimesityl borinic acid, Mes(2)BOH (Mes = mesityl), affords Zn(3)(hpp)(4)(OBMes(2))(2) 14 in which the trimetallic core is retained. This reactivity is in contrast to the closely related reaction of dimeric Zn[Me(2)NC[N(i)Pr](2)]Me 15 with Mes(2)BOH, which yielded Zn[Me(2)NC[N(i)Pr](2)][OBMes(2)].Me(2)NC[N(i)Pr][NH(i)Pr] 16 as a result of protonation at the guanidine ligand in addition to the Zn-Me bond.     

Crystal Structure of （E,E）-1,10-Bis-（4-fluoro-phenyl）-3,8-dimethyl-deca-3,7-diene-1,10-dione

1 INTRODUCTION The direct use of metallic samarium as the re-ducing agent in organic transformations has attractedthe attention of many organic chemists[1]. In our inves-tigations on the applications of metallic samarium inorganic synthesis, we have recently found that me-tallic samarium exhibits some extraordinary capa-bilities when DMF instead of traditional THF wasused as the reaction medium[2]. β,γ-Unsaturated car-bonyl moieties, known to exist in natural products,serve as versati…     

Synthesis and characterization of mono- and binuclear platinum complexes containing terminal and bridging diynyldiphenylphosphine ligands

A series of mononuclear platinum complexes containing diynyldiphenylphosphine ligands [cis-Pt(C(6)F(5))(2)(PPh(2)C[triple bond]CC(6)H(4)C[triple bond]CR)L](n)(n= 0, L = tht, R = Ph 2a, Bu(t)2b; L = PPh(2)C[triple bond]CC(6)H(4)C[triple bond]CR, 4a, 4b; n=-1, L = CN(-), 3a, 3b) has been synthesized and the X-ray crystal structures of 4a and 4b have been determined. In order to compare the eta2-bonding capability of the inner and outer alkyne units, the reactivity of towards [cis-Pt(C(6)F(5))(2)(thf)(2)] or [Pt(eta2)-C(2)H(4))(PPh(3))(2)] has been examined. Complexes coordinate the fragment "cis-Pt(C(6)F(5))(2)" using the inner alkynyl fragment and the sulfur of the tht ligand giving rise the binuclear derivatives [(C(6)F(5))(2)Pt(mu-tht)(mu-1kappaP:2eta2-C(alpha),C(beta)-PPh(2)C[triple bond]CC(6)H(4)C[triple bond]CR)Pt(C(6)F(5))(2)](R = Ph 5a, Bu(t)5b). The phenyldiynylphosphine complexes 2a, 3a and 4a react with [Pt(eta2)-C(2)H(4))(PPh(3))(2)] to give the mixed-valence Pt(II)-Pt(0) complexes [((C(6)F(5))(2)LPt(mu-1kappaP:2eta2)-C(5),C(6)-PPh(2)C[triple bond]CC(6)H(4)C[triple bond]CPh))Pt(PPh(3))(2)](n)(L = tht 6a, CN 8a and PPh(2)C[triple bond]CC(6)H(4)C[triple bond]CPh 9a) in which the Pt(0) fragment is eta2-complexed by the outer fragment. Complex 6a isomerizes in solution to a final complex [((C(6)F(5))(2)(tht)Pt(mu-1kappaP:2eta2)-C(alpha),C(beta)-PPh(2)C[triple bond]CC(6)H(4)C[triple bond]CPh))Pt(PPh(3))(2)]7a having the Pt(0) fragment coordinated to the inner alkyne function. In contrast, the tert-butyldiynylphosphine complexes 2b and 3b coordinate the Pt(0) unit through the phosphorus substituted inner acetylenic entity yielding 7b and 8b. By using 4a and 2 equiv. of [Pt(eta2)-C(2)H(4))(PPh(3))(2)] as precursors, the synthesis of the trinuclear complex [cis-((C(6)F(5))(2)Pt(mu-1kappaP:2eta2)-C(5),C(6)-PPh(2)C[triple bond]CC(6)H(4)C[triple bond]CPh)(2))(Pt(PPh(3))(2))(2)]10a, bearing two Pt(0)(PPh(3))(2)eta2)-coordinated to the outer alkyne functions is achieved. The structure of 7a has been confirmed by single-crystal X-ray diffraction.     

(R)-N-乙酰基-四氢噻唑-2-硫酮-4-甲酰TT的合成及其晶体结构

由N-乙酰(R)-四氢噻唑-2-硫酮-4-羧酸在三聚氯氰及三乙胺存在下与四氢噻唑-2-硫酮反应得到标题化合物，[α]^2^0~D +11.18°。用X射线衍射法测得其晶体结构，属单斜晶系，空间群为P2~1/c。晶体学数据：a=0.9959(4)nm，b=1.1469(4)nm，c=1.1108(3)nm，β=92.72(3)°，V=1.2673(8)nm^3，Z=4。分子中两个C=O基，两个C=S基团处于C(1)-N(1)-C(4)及C(6)-N(2)-C(7)键两侧呈反式。用PM3分子轨道方法研究了该化合物的电子结构，电荷和键序分布，得到该化合物前线轨道性质。     

Synthesis and Crystal Structure of Tetramethyl 4aH-Pyrido [1, 2-a] Quinoline-1,2,3,4-Tetracarboxylate

1 INTRODUCTION Alkaloids and their derivatives are ubiquitous in natural products, and most of those compounds are of biological activities. Therefore, the structure modifi- cation of alkaloids is always the point that organic chemists and medicinal chemists focus on[1~10]. Qui- nolizine ring system is an important kind of alkaloid, which has a nitrogen atom shared by two six-mem- bered rings. Many medicines have quinolizine ring system, such as reserpine[11, 12] and berberine[13]. How- …     

Carbenerhodium complexes of the half-sandwich-type: synthesis, substitution, and addition reactions

A series of carbenerhodium(I) complexes of the general composition [(eta5-C5H5)Rh(=CRR')(L)] (2a-2i) with R = R'= aryl and L = SbiPr3 or PR3 has been prepared from the square-planar precursors trans-[RhCl(=CRR')(L)2] and NaC5H5 in excellent yields. Reaction of the triisopropylsibane derivative 2a. which contains a rather labile Rh-Sb bond, with CO, PMe3, and CNR (R = Me, CH2Ph, tBu) leads to the displacement of the SbiPr3 ligand and affords the substitution products [(eta5-C5H5)Rh(=CPh2)(L)] (3-7). In contrast, treatment of the triisopropylphosphane compound 2c with CO and CNtBu leads to the cleavage of the Rh=CPh2 bond and gives besides [(eta5-C5H5)Rh(PiPr3)(L)] (10, 12) by metal-assisted C-C coupling diphenylketene Ph2C=C=O (11) or the corresponding imine Ph2C=C=NtBu (13). While the reaction of 2a, c with C2H4 yields [(eta5-C5H5)Rh(C2H4)(L)] (14, 15) and the trisubstituted olefin Ph2C=CHCH3 (16), treatment of 2a, c with RN3 leads to the cleavage of both the Rh-EiPr3 and Rh=CPh2 bonds and gives the chelate complexes [(eta5-C5H5)Rh(kappa2-RNNNNR)] (19, 20). The substitution products 3 (L=CO) and 4 (L= PMe3) react with an equimolar amount of sulfur or selenium by addition of the chalcogen to the Rh=CPh2 bond to generate the complexes [(eta5-C5H5)Rh(kappa2-ECPh2)(L)] (21-24) with thio- or selenobenzophenone as ligand. Similarly, treatment of 3 with CuCl affords the unusual 1:2 adduct [(eta5-C5H5)(CO)Rh(mu-CPh2)(CuCl)2] (25), which reacts with NaC5H5 to form [(eta5-C5H5)(CO)Rh(muCPh2)Cu(eta5-C5H5)] (26). The molecular structures of 3 and 22 have been determined by X-ray crystallography.     

Study of the thymine molecule: equilibrium structure from joint analysis of gas-phase electron diffraction and microwave data and assignment of vibrational spectra using results of ab initio calculations

Thymine is one of the nucleobases which forms the nucleic acid (NA) base pair with adenine in DNA. The study of molecular structure and dynamics of nucleobases can help to understand and explain some processes in biological systems and therefore it is of interest. Because the scattered intensities on the C, N, and O atoms as well as some bond lengths in thymine are close to each other the structural problem cannot been solved by the gas phase electron diffraction (GED) method alone. Therefore the rotational constants from microvawe (MW) studies and differences in the groups of N-C, C=O, N-H, and C-H bond lengths from MP2 (full)/cc-pVQZ calculations were used as supplementary data. The analysis of GED data was based on the C(s) molecular symmetry according to results of the structure optimizations at the MP2 (full) level using 6-311G (d,p), cc-pVTZ, and cc-pVQZ basis sets confirmed by vibrational frequency calculations with 6-311G (d,p) and cc-pVTZ basis sets. Mean-square amplitudes as well as harmonic and anharmonic vibrational corrections to the internuclear distances (r(e)-r(a)) and to the rotational constants (B(e)(k)-B(0)(k), where k = A, B, C) were calculated from the quadratic (MP2 (full)/cc-pVTZ) and cubic (MP2 (full)/6-311G (d,p)) force constants (the latter were used only for anharmonic corrections). The harmonic force field was scaled using published IR and Raman spectra of the parent and N1,N3-dideuterated species, which were for the first time completely assigned in the present work. The main equilibrium structural parameters of the thymine molecule determined from GED data supplemented by MW rotational constants and results of MP2 calculations are the following (bond lengths in Angstroms and bond angles in degrees with 3sigma in parentheses): r(e) (C5=C6) = 1.344 (16), r(e) (C5-C9) = 1.487 (8), r(e) (N1-C6) = 1.372 (3), r(e) (N1-C2) = 1.377 (3), r(e) (C2-N3) = 1.378 (3), r(e) (N3-C4) = 1.395 (3), r(e) (C2=O7) = 1.210 (1), r(e) (C4=O8) = 1.215 (1), angle e (N1-C6=C5) = 123.1 (5), angle e (C2-N1-C6) = 123.7 (5), angle e (N1-C2-N3) = 112.8 (5), angle e (C2-N3-C4) = 128.0 (5), angle e (N3-C4-C5) = 114.8 (5), angle e (C6=C5-C9) = 124.4 (9). The experimental structural parameters are in good agreement with those from MP2 (full) calculations with use of cc-pVTZ and cc-pVQZ basis sets.     

Crystal Structure of (1R,4R;1S,4S)2-Amino-3-Cyano-1,4-Diphenyl-2-Cyclopentene-1-ol

1INTRODUCTIONIntheearly1970'sthreegroupsofinvestigatorsL,~,'foundthatlow-valenttita-nium,preparedbythereactionofstrongreducingagentswithtitaniumtrichlorideortitaniumtetrachlorideintetrahydrofuran,canabstractoxygenfromketonesoraldehydes,leadingtotheforma-tionofolefins.Theinterestinthereactioninducedbylow--valenttitaniumreagentsisincreasingandalargenumberoffunctionalgroupscanbereduceds4-6).Recent-ly,wefoundthatthetitlecompoundisObtainedbycy-cllzatlonreactionof(3--oxo-1,3-diphenyl)propyl-pro…     

trans—和cis—(η~5—C_5Me_5)2Mo_2(μ_2—S)_2(t—O)_2[Me=CH_3—]的合成和结构

trans—(η~5—C_5Me_5)_2Mo_2(μ_2—S)_2(t—O)_2[Ⅰ]和cis—(η~5—C_5Me_5)Mo_2(μ_2—O)_2(t—O)_2(Ⅱ]是由Mo(CO)_6和C_5(CH_3)_5H的反应产物(η~5—C_5Me_5)_2Mo_2(CO)_4与(CH_2)_3S反应中同时得到的。晶体[Ⅰ]属四方晶系,空间群为P4_2/n,单胞参数;a=b=16.317,c=8.463,V=2253.16,Z=4。晶体[Ⅱ]亦属四方晶系,空间群为P42_1c,单胞参数:a=b=12.101,c=15.425,V=2258.54,Z=4 [Ⅰ]和[Ⅱ]分子分别具有C_1—T和C_2—2对称性。如把C_5Me_5-看成具有理想的园柱体对称性,则它们分别具有C_(2h)—2/m和C_(2v)—mm2对称性。在[Ⅰ]中Mo_2(μ_2—S)_2为菱形平面结构,而[Ⅱ]中则畸变成“蝶式”结构。由两个钼原子之间的距离(2.902和2.808)可以看出钼一钼间作用属于单键的范围内。所以它们是具有金属单键的双钼金属簇的两个立体异构体。     

Molecular structure, conformation, and potential to internal rotation of 2,6- and 3,5-difluoronitrobenzene studied by gas-phase electron diffraction and quantum chemical calculations

3,5-Difluoronitrobenzene (3,5-DFNB) and 2,6-difluoronitrobenzene (2,6-DFNB) have been studied by gas-phase electron diffraction (GED), MP2 ab initio, and by B3LYP density functional calculations. Refinements of r h1 and r e static and r h1 dynamic GED models were carried out for both molecules. Equilibrium r e structures were determined using anharmonic vibrational corrections to the internuclear distances ( r e - r a) calculated from B3LYP/cc-pVTZ cubic force fields. 3,5-DFNB possesses a planar structure of C 2 v symmetry with the following r e values for bond lengths and bond angles: r(C-C) av = 1.378(4) A, r(C-N) = 1.489(6) A, r(N-O) = 1.217(2) A, r(C-F) = 1.347(5) A, angleC6-C1-C2 = 122.6(6) degrees , angleC1-C2-C3 = 117.3(3) degrees , angleC2-C3-C4 = 123.0(3) degrees , angleC3-C4-C5 = 116.9(6) degrees , angleC-C-N = 118.7(3) degrees , angleC-N-O = 117.3(4) degrees , angleO-N-O = 125.5(7) degrees , angleC-C-F = 118.6(7) degrees . The uncertainties in parentheses are three times the standard deviations. As in the case of nitrobenzene, the barrier to internal rotation of the nitro group in 3,5-DFNB, V 90 = 10 +/- 4 kJ/mol, is substantially lower than that predicted by quantum chemical calculations. The presence of substituents in the ortho positions force the nitro group to rotate about the C-N bond, out of the plane of the benzene ring. For 2,6-DFNB, a nonplanar structure of C 2 symmetry with a torsional angle of phi(C-N) = 53.8(14) degrees and the following r e values for structural parameters was determined by the GED analysis: r(C-C) av = 1.383(5) A, r(C-N) = 1.469(7) A, r(N-O) = 1.212(2) A, r(C-F) = 1.344(4) A, angleC6-C1-C2 = 118.7(5) degrees , angleC1-C2-C3 = 121.2(2) degrees , angleC2-C3-C4 = 119.0(2) degrees , angleC3-C4-C5 = 121.1(4) degrees , angleC-C-N = 120.6(2) degrees , angleC-N-O = 115.7(4) degrees , angleO-N-O = 128.6(7) degrees , angleC-C-F = 118.7(5) degrees . The refinement of a dynamic model led to barriers V 0 = 16.5 +/- 1.5 kJ/mol and V 90 = 2.2 +/- 0.5 kJ/mol, which are in good agreement with values predicted by B3LYP/6-311++G(d,p) and MP2/ cc-pVTZ calculations. The values of C-F bond lengths are similar in both molecules. This is in contrast to the drastic shortening of the C-F bond in the ortho position in 2-fluoronitrobenzene compared to the C-F bond length in the meta and para position in 3- and 4-fluoronitrobenzene observed in an earlier GED study.     

C-F activation of fluorinated arenes using NHC-stabilized nickel(0) complexes: selectivity and mechanistic investigations

The reaction of [Ni2((i)Pr2Im)4(COD)] 1a or [Ni((i)Pr2Im)2(eta(2)-C2H4)] 1b with different fluorinated arenes is reported. These reactions occur with a high chemo- and regioselectivity. In the case of polyfluorinated aromatics of the type C6F5X such as hexafluorobenzene (X = F) octafluorotoluene (X = CF3), trimethyl(pentafluorophenyl)silane (X = SiMe3), or decafluorobiphenyl (X = C6F5) the C-F activation regioselectively takes place at the C-F bond in the para position to the X group to afford the complexes trans-[Ni((i)Pr2Im)2(F)(C6F5)]2, trans-[Ni((i)Pr2Im)2(F)(4-(CF3)C6F4)] 3, trans-[Ni((i)Pr2Im)2(F)(4-(C6F5)C6F4)] 4, and trans-[Ni((i)Pr2Im)2(F)(4-(SiMe3)C6F4)] 5. Complex 5 was structurally characterized by X-ray diffraction. The reaction of 1a with partially fluorinated aromatic substrates C6H(x)F(y) leads to the products of a C-F activation trans-[Ni((i)Pr2Im)2(F)(2-C6FH4)] 7, trans-[Ni((i)Pr2Im)2(F)(3,5-C6F2H3)] 8, trans-[Ni((i)Pr2Im)2(F)(2,3-C6F2H3)] 9a and trans-[Ni((i)Pr2Im)2(F)(2,6-C6F2H3)] 9b, trans-[Ni((i)Pr2Im)2(F)(2,5-C6F2H3)] 10, and trans-[Ni((i)Pr2Im)2(F)(2,3,5,6-C6F4H)] 11. The reaction of 1a with octafluoronaphthalene yields exclusively trans-[Ni((i)Pr2Im)2(F)(1,3,4,5,6,7,8-C10F7)] 6a, the product of an insertion into the C-F bond in the 2-position, whereas for the reaction of 1b with octafluoronaphthalene the two isomers trans-[Ni((i)Pr2Im)2(F)(1,3,4,5,6,7,8-C10F7)] 6a and trans-[Ni((i)Pr2Im)2(F)(2,3,4,5,6,7,8-C10F7)] 6b are formed in a ratio of 11:1. The reaction of 1a or of 1b with pentafluoropyridine at low temperatures affords trans-[Ni((i)Pr2Im)2(F)(4-C5NF4)] 12a as the sole product, whereas the reaction of 1b performed at room temperature leads to the generation of trans-[Ni((i)Pr2Im)2(F)(4-C5NF4)] 12a and trans-[Ni((i)Pr2Im)2(F)(2-C5NF4)] 12b in a ratio of approximately 1:2. The detection of intermediates as well as kinetic studies gives some insight into the mechanistic details for the activation of an aromatic carbon-fluorine bond at the {Ni((i)Pr2Im)2} complex fragment. The intermediates of the reaction of 1b with hexafluorobenzene and octafluoronaphthalene, [Ni((i)Pr2Im)2(eta(2)-C6F6)] 13 and [Ni((i)Pr2Im)2(eta(2)-C10F8)] 14, have been detected in solution. They convert into the C-F activation products. Complex 14 was structurally characterized by X-ray diffraction. The rates for the loss of 14 at different temperatures for the C-F activation of the coordinated naphthalene are first order and the estimated activation enthalpy Delta H(double dagger) for this process was determined to be Delta H(double dagger) = 116 +/- 8 kJ mol(-1) (Delta S(double dagger) = 37 +/- 25 J K(-1) mol(-1)). Furthermore, density functional theory calculations on the reaction of 1a with hexafluorobenzene, octafluoronaphthalene, octafluorotoluene, 1,2,4-trifluorobenzene, and 1,2,3-trifluorobenzene are presented.     

Syntheses and structures of heterometallic clusters by the reaction of o-carboranyl cobaltadichalcogenolato complexes

Metalladichalcogenolate cluster complexes [Cp'Co{E(2)C(2)(B(10)H(10))}]{Co2(CO)5} [Cp' = eta5-C5H5, E = S(3a), E = Se(3b); Cp' = eta5-C5(CH3)5, E = S(4a), E = Se(4b)], {CpCo[E(2)C(2)(B(10)H(10))]}(2)Mo(CO)2] [E = S(5a), Se(5b)], Cp*Co(micro2-CO)Mo(CO)(py)2[E(2)C(2)(B(10)H(10))] [E = S(6a), Se(6b)], Cp*Co[E(2)C(2)(B(10)H(10))]Mo(CO)2[E(2)C(2)(B(10)H(10))] [E = S(7a), Se(7b)], (Cp'Co[E(2)C(2)(B(10)H(10))]W(CO)2 [E(2)C(2)(B(10)H(10))] [Cp' = eta5-C5H5, E = S(8a), E = Se(8b); Cp' = eta5-C5(CH3)5, E = S(9a), E = Se(9b)], {CpCo[E(2)C(2)(B(10)H(10))]}(2)Ni [E = S(10a), Se(10b)] and 3,4-(PhCN(4)S)-3,1,2-[PhCN(4)SCo(Cp)S(2)]-3,1,2-CoC(2)B(9)H(8) 12 were synthesized by the reaction of [Cp'CoE(2)C(2)(B(10)H(10))] [Cp' = eta5-C5H5, E = S(1a), E = Se(1b); Cp' = eta5-C5(CH3)5, E = S(2a), E = Se(2b)] with Co2(CO)8, M(CO)3(py)3 (M = Mo, W), Ni(COD)2, [Rh(COD)Cl]2, and LiSCN4Ph respectively. Their spectrum analyses and crystal structures were investigated. In this series of multinuclear complexes, 3a,b and 4a,b contain a closed Co3 triangular geometry, while in complexes 5a-7b three different structures were obtained, the tungsten-cobalt mixed-metal complexes have only the binuclear structure, and the nickel-cobalt complexes were obtained in the trinuclear form. A novel structure was found in metallacarborane complex 12, with a B-S bond formed at the B(7) site. The molecular structures of 4a, 5a, 6a, 7b, 9a, 9b, 10a and 12 have been determined by X-ray crystallography.