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1.
Vincenzo G Albano Fabio Marchetti Stefano Zacchini 《Journal of organometallic chemistry》2004,689(3):528-538
Terminal alkynes (HCCR′) (R′=COOMe, CH2OH) insert into the metal-carbyne bond of the diiron complexes [Fe2{μ-CN(Me)(R)}(μ-CO)(CO)(NCMe)(Cp)2][SO3CF3] (R=Xyl, 1a; CH2Ph, 1b; Me, 1c; Xyl=2,6-Me2C6H3), affording the corresponding μ-vinyliminium complexes [Fe2{μ-σ:η3-C(R′)CHCN(Me)(R)}(μ-CO)(CO)(Cp)2][SO3CF3] (R=Xyl, R′=COOMe, 2; R=CH2Ph, R′=COOMe, 3; R=Me, R′=COOMe, 4; R=Xyl, R′=CH2OH, 5; R=Me, R′=CH2OH, 6). The insertion is regiospecific and C-C bond formation selectively occurs between the carbyne carbon and the CH moiety of the alkyne. Disubstituted alkynes (R′CCR′) also insert into the metal-carbyne bond leading to the formation of [Fe2{μ-σ:η3-C(R′)C(R′)CN(Me)(R)}(μ-CO)(CO)(Cp)2][SO3CF3] (R′=Me, R=Xyl, 8; R′=Et, R=Xyl, 9; R′=COOMe, R=Xyl, 10; R′=COOMe, R=CH2Ph, 11; R′=COOMe, R=Me, 12). Complexes 2, 3, 5, 8, 9 and 11, in which the iminium nitrogen is unsymmetrically substituted, give rise to E and/or Z isomers. When iminium substituents are Me and Xyl, the NMR and structural investigations (X-ray structure analysis of 2 and 8) indicate that complexes obtained from terminal alkynes preferentially adopt the E configuration, whereas those derived from internal alkynes are exclusively Z. In complexes 8 and 9, trans and cis isomers have been observed, by NMR spectroscopy, and the structures of trans-8 and cis-8 have been determined by X-ray diffraction studies. Trans to cis isomerization occurs upon heating in THF at reflux temperature. In contrast to the case of HCCR′, the insertion of 2-hexyne is not regiospecific: both [Fe2{μ-σ:η3-C(CH2CH2CH3)C(Me)CN(Me)(R)}(μ-CO)(CO)(Cp)2][SO3CF3] (R=Xyl, 13; R=Me, 15) and [Fe2{μ-σ:η3-C(Me)C(CH2CH2CH3)CN(Me)(R)}(μ-CO)(CO)(Cp)2][SO3CF3] (R=Xyl, 14, R=Me, 16) are obtained and these compounds are present in solution as a mixture of cis and trans isomers, with predominance of the former. 相似文献
2.
《Polyhedron》1986,5(4):951-958
The chromium(0) complexes Cr(CO)3(CNR)(R′-DAB) (R = Me, CHMe2, CMe3, or xylyl; R′ = i-Pr, t-Bu, Cy or p-tol) can be prepared by the reaction of Cr(CO)3(NCMe)3 with equimolar quantities of R′-DAB and RNC. These complexes are oxidized to the paramagnetic 17-electron salts [Cr(CO)3(CNR)(R′-DAB)]PF6 by [(η5-C5H5)2Fe]Pf6 in ethanol, and can be reduced to the paramagnetic 19-electron radical anions [Cr(CO)3(CNR)(R′-DAB)]− using NaHg in tetrahydrofuran. The spectroscopic (IR, 1H NMR, electronic absorption and ESR) and electrochemical properties of the [Cr(CO)3(CNR)(R′-DAB)]1+,0,1′ species (where appropriate) have been recorded. The dark red monocationic species [Cr(CO)3(CNR)(R′-DAB)]PF6 are subject to disproportionation in solution to give separable mixtures of dark blue Cr(CO)3(CNR)(R′-DAB) and green [Cr(CNR)4(R′-DAB)](PF6)2. 相似文献
3.
Oxidation of the complexes -[M(CNR)2(dppe)2] (A) (M = Mo or W; R = Me, But or CH3C6H4-; dppe = Ph2PCH2CH2PPh2) with diiodine or silver (I) salts gives the paramagnetic cations -[M(CNR)2(dppe)2]+, (M = Mo, R = CH3C6H4-; M = W, R = But) and -[M(CNR)2(dppe)2]2+ (M = Mo, R = Me or CH3C6H4-; M = W, R = Me or But). Mixtures of products are generally produced when dichlorine or dibromine are the oxidising agents, however pure salts, the seven-coordinate complex cations [MX(CNC6H4CH3-)2(dppe)2]+ (B, X = Cl or Br) have been isolated. A simple molecular orbital scheme is proposed for complexes (A) and used to discuss their electronic spectra and their oxidation. 相似文献
4.
Diimido, Imido Oxo, Dioxo, and Imido Alkylidene Halfsandwich Compounds via Selective Hydrolysis and α—H Abstraction in Molybdenum(VI) and Tungsten(VI) Organyl Complexes Organometal imides [(η5‐C5R5)M(NR′)2Ph] (M = Mo, W, R = H, Me, R′ = Mes, tBu) 4 — 8 can be prepared by reaction of halfsandwich complexes [(η5‐C5R5)M(NR′)2Cl] with phenyl lithium in good yields. Starting from phenyl complexes 4 — 8 as well as from previously described methyl compounds [(η5‐C5Me5)M(NtBu)2Me] (M = Mo, W), reactions with aqueous HCl lead to imido(oxo) methyl and phenyl complexes [(η5‐C5Me5)M(NtBu)(O)(R)] M = Mo, R = Me ( 9 ), Ph ( 10 ); M = W, R = Ph ( 11 ) and dioxo complexes [(η5‐C5Me5)M(O)2(CH3)] M = Mo ( 12 ), M = W ( 13 ). Hydrolysis of organometal imides with conservation of M‐C σ and π bonds is in fact an attractive synthetic alternative for the synthesis of organometal oxides with respect to known strategies based on the oxidative decarbonylation of low valent alkyl CO and NO complexes. In a similar manner, protolysis of [(η5‐C5H5)W(NtBu)2(CH3)] and [(η5‐C5Me5)Mo(NtBu)2(CH3)] by HCl gas leads to [(η5‐C5H5)W(NtBu)Cl2(CH3)] 14 und [(η5‐C5Me5)Mo(NtBu)Cl2(CH3)] 15 with conservation of the M‐C bonds. The inert character of the relatively non‐polar M‐C σ bonds with respect to protolysis offers a strategy for the synthesis of methyl chloro complexes not accessible by partial methylation of [(η5‐C5R5)M(NR′)Cl3] with MeLi. As pure substances only trimethyl compounds [(η5‐C5R5)M(NtBu)(CH3)3] 16 ‐ 18 , M = Mo, W, R = H, Me, are isolated. Imido(benzylidene) complexes [(η5‐C5Me5)M(NtBu)(CHPh)(CH2Ph)] M = Mo ( 19 ), W ( 20 ) are generated by alkylation of [(η5‐C5Me5)M(NtBu)Cl3] with PhCH2MgCl via α‐H abstraction. Based on nmr data a trend of decreasing donor capability of the ligands [NtBu]2— > [O]2— > [CHR]2— ? 2 [CH3]— > 2 [Cl]— emerges. 相似文献
5.
Synthesis, characterization and cyclic voltammetric studies of β-ketooximato ruthenium(II) complexes
Summary
-Ketooxime [RC(O)C(NOH)R] (R = Me or Ph) ligands (HL) react with [Ru(PPh3)3Cl2] in refluxing EtOH to yield [Ru(PPh3)2(L)2] complexes. For R = Me, one isomer was obtained, while two isomers were isolated when R = Ph, due to a bulk effect. The complexes are diamagnetic and absorb intensely in the vis. region due to MLCT transitions. In MeCN and CH2Cl2 solution, RuII-RuIII oxidation occurs in the 0.69–0.92 V versus s.c.e. range. The oxidation potential depends on both the electronic nature of R and the stereochemistry of the complexes. 相似文献
6.
The complexation of zinc(II) with chloride, bromide and iodide ions has been studied by calorimetry in hexamethylphosphoric triamide (HMPA) containing 0.1 mol-dm–3 (n-C4H9)4NClO4 as a constant ionic medium at 25°C. The formation of [ZnXn](2–n)+ (n=1,2,3,4 for X=Cl; n=1,2 for X=Br, I) is revealed, and their formation constants, enthalpies and entropies were determined. It is proposed that the zinc(II) ion is fourcoordinated in HMPA and the coordinating HMPA molecules are stepwise replaced with halide ions to form [ZnXn(hmpa)4–n](2–n)+ (n=1–4), as is the case for the cobalt(II) ion. Furthermore, the formation of [ZnClI], [ZnBrI], [ZnBrCl] and [ZnBrCl2]– is revealed in the relevant ternary systems. It is found that the affinity of a given halide ion X– to [ZnCl]+, [ZnBr]+ and [Znl]+ is practically the same. 相似文献
7.
Yanfeng Jiang Olivier Blacque Dr. Thomas Fox Dr. Christian M. Frech Dr. Heinz Berke Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(7):2240-2249
The five‐coordinated ReI hydride complexes [Re(Br)(H)(NO)(PR3)2] (R=Cy 1 a , iPr 1 b ) were reacted with benzylbromide, thereby affording the 17‐electron mononuclear ReII hydride complexes [Re(Br)2(H)(NO)(PR3)2] (R=Cy 3 a , iPr 3 b ), which were characterized by EPR, cyclic voltammetry, and magnetic susceptibility measurements. In the case of dibromomethane or bromoform, the reaction of 1 afforded ReII hydrides 3 in addition to ReI carbene hydrides [Re(?CHR1)(Br)(H)(NO)(PR3)2] (R1=H 4 , Br 5 ; R=Cy a , iPr b ) in which the hydride ligand is positioned cis to the carbene ligand. For comparison, the dihydrogen ReI dibromide complexes [Re(Br)2(NO)(PR3)2(η2‐H2)] (R=Cy 2 a , iPr 2 b ) were reacted with allyl‐ or benzylbromide, thereby affording the monophosphine ReII complex salts [R3PCH2R′][Re(Br)4(NO)(PR3)] (R′=? CH?CH2 6 , Ph 7 ). The reduction of ReII complexes has also been examined. Complex 3 a or 3 b can be reduced by zinc to afford 1 a or 1 b in high yield. Under catalytic conditions, this reaction enables homocoupling of benzylbromide (turnover frequency (TOF): 3 a 150, 3 b 134 h?1) or allylbromide (TOF: 3 a 575, 3 b 562 h?1). The reaction of 6 a and 6 b with zinc in acetonitrile affords in good yields the monophosphine ReI complexes [Re(Br)2(NO)(MeCN)2(PR3)] (R=Cy 8 a , iPr 8 b ), which showed high catalytic activity toward highly selective dehydrogenative silylation of styrenes (maximum TOF of 61 h?1). Single‐electron transfer (SET) mechanisms were proposed for all these transformations. The molecular structures of 3 a , 6 a , 6 b , 7 a , 7 b , and 8 a were established by single‐crystal X‐ray diffraction studies. 相似文献
8.
Chiral (1,2)‐Diphenylethylene‐Salen Complexes of Triel Metals: Coordination Patterns and Mechanistic Considerations in the Isoselective ROP of Lactide
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Nicolas Maudoux Dr. Thierry Roisnel Dr. Vincent Dorcet Prof. Dr. Jean‐François Carpentier Dr. Yann Sarazin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(20):6131-6147
The synthesis of enantiomerically pure aluminium, gallium and indium complexes supported by chiral (R,R)‐(HHONNOHH) ( 1 ), (R,R)‐(MeHONNOHMe) ( 2 ), (R,R)‐(tButBuONNOtButBu) ( 3 ), (R,R)‐(MeNO2ONNOMeNO2) ( 4 ), (R,R)‐(HOMeONNOHOMe) ( 5 ) and (R,R)‐(ClClONNOClCl) ( 6 ) (1,2)‐diphenylethylene‐salen ligands is described. Several of these complexes have been crystallographically authenticated, which highlights a diversity of coordination patterns. Whereas all Ga complexes form [Ga2(CH2SiMe3)4(ONNO)] bimetallic species (ONNO= 1 – 3 ), aluminium [AlR(ONNO)] (R=Me, CH2SiMe3) and indium [In(CH2SiMe3)(ONNO)] derivatives are monometallic for ONNO= 1 , 2 and 4 – 6 , and only form the bimetallic complexes [Al2R4(ONNO)] and [In2(CH2SiMe3)4(ONNO)] for the most sterically crowded ligand 3 . The [AlMe(ONNO)] complexes react with iPrOH to give [AlOiPr(ONNO)] complexes that are robust towards further iPrOH. The [In(CH2SiMe3)(ONNO)] congeners are inert towards excess alcohol, whereas the Ga compounds decompose easily. All these alkyl complexes, as well as the [AlOiPr(ONNO)] derivatives, catalyse the ring‐opening polymerisation (ROP) of racemic lactide (rac‐LA). The [AlMe(ONNO)] complexes require additional alcohol to afford controlled reactions, but [AlOiPr(ONNO)] complexes are single‐component catalysts for the isoselective ROP of rac‐LA, with values of Pm in the range 0.80–0.90. Experimental evidence unexpectedly shows that chain‐end control leads to the isoselectivity of these aluminium catalysts; also, the more crowded the coordination sphere, the higher the isoselectivity. The bimetallic Ga complexes do not afford controlled reactions, but the binary [In(ONNO)(CH2SiMe3)/(PhCH2OH)] systems competently mediate non‐stereoselective ROP; evidence is given that an activated monomer mechanism is at work. Kinetic studies show that catalytic activity decreases when electronic density and steric congestion at the metal atom increase. 相似文献
9.
3‐Rhoda‐1,2‐diazacyclopentanes: A Series of Novel Metallacycle Complexes Derived From CN Functionalization of Ethylene
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Marcus W. Drover Daniel W. Beh Prof. Dr. Pierre Kennepohl Prof. Dr. Jennifer A. Love 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(41):13345-13355
Rh‐containing metallacycles, [(TPA)RhIII(κ2‐(C,N)‐CH2CH2(NR)2‐]Cl; TPA=N,N,N,N‐tris(2‐pyridylmethyl)amine have been accessed through treatment of the RhI ethylene complex, [(TPA)Rh(η2‐CH2CH2)]Cl ([ 1 ]Cl) with substituted diazenes. We show this methodology to be tolerant of electron‐deficient azo compounds including azo diesters (RCO2N?NCO2R; R=Et [ 3 ]Cl, R=iPr [ 4 ]Cl, R=tBu [ 5 ]Cl, and R=Bn [ 6 ]Cl) and a cyclic azo diamide: 4‐phenyl‐1,2,4‐triazole‐3,5‐dione (PTAD), [ 7 ]Cl. The latter complex features two ortho‐fused ring systems and constitutes the first 3‐rhoda‐1,2‐diazabicyclo[3.3.0]octane. Preliminary evidence suggests that these complexes result from N–N coordination followed by insertion of ethylene into a [Rh]?N bond. In terms of reactivity, [ 3 ]Cl and [ 4 ]Cl successfully undergo ring‐opening using p‐toluenesulfonic acid, affording the Rh chlorides, [(TPA)RhIII(Cl)(κ1‐(C)‐CH2CH2(NCO2R)(NHCO2R)]OTs; [ 13 ]OTs and [ 14 ]OTs. Deprotection of [ 5 ]Cl using trifluoroacetic acid was also found to give an ethyl substituted, end‐on coordinated diazene [(TPA)RhIII(κ2‐(C,N)‐CH2CH2(NH)2‐]+ [ 16 ]Cl, a hitherto unreported motif. Treatment of [ 16 ]Cl with acetyl chloride resulted in the bisacetylated adduct [(TPA)RhIII(κ2‐(C,N)‐CH2CH2(NAc)2‐]+, [ 17 ]Cl. Treatment of [ 1 ]Cl with AcN?NAc did not give the Rh?N insertion product, but instead the N,O‐chelated complex [(TPA)RhI ( κ2‐(O,N)‐CH3(CO)(NH)(N?C(CH3)(OCH?CH2))]Cl [ 23 ]Cl, presumably through insertion of ethylene into a [Rh]?O bond. 相似文献
10.
New mixed ligand complexes of copper(II) dithiocarbamates of the general formula, [CuCl(R2dtc)L] or [CuCi(R′ dtc)L] (RCH3 or C2H5, R′ = (CH2)5, dtc =-NCSS? and L = Pyridine, 3-picoline or 4-picoline), have been prepared by the reaction of bis(dithiocarbamato)di-μ-chloro-dicopper(II) complexes with pyridine or picolines. The complexes are found to be non-electrolytes in nitrobenzene. Magnetic susceptibilities, i.r. and electronic spectra of the complexes are reported. A psuedo-tetrahedral structure is suggested for these complexes. 相似文献
11.
The complexes [M(CO)4(pyridyl‐CH=N‐CHRCO2R′)] (M = Cr, Mo; R = H, CH3, CH(CH3)2, CH2CH(CH3)2) were obtained by reaction of the Schiff bases from pyridine‐2‐carboxaldehyde and glycine, L‐alanine, L‐valine or L‐leucine esters with the norbornadiene complexes [M(CO)4(nbd)] and were characterized by IR, 1H and 13C NMR and UV‐vis spectra. The deeply colored complexes exhibit solvatochromism. 相似文献
12.
Juan Forniés Violeta Sicilia Pilar Borja José M. Casas Alvaro Díez Elena Lalinde Carmen Larraz Antonio Martín M. Teresa Moreno 《化学:亚洲杂志》2012,7(12):2813-2823
The neutral compounds [Pt(bzq)(CN)(CNR)] (R=tBu ( 1 ), Xyl ( 2 ), 2‐Np ( 3 ); bzq= benzoquinolate, Xyl=2,6‐dimethylphenyl, 2‐Np=2‐napthyl) were isolated as the pure isomers with a trans‐Cbzq,CNR configuration, as confirmed by 13C{1H} NMR spectroscopy in the isotopically marked [Pt(bzq)(13CN)(CNR)] (R=tBu ( 1′ ), Xyl ( 2′ ), 2‐Np ( 3′ )) derivatives (δ13CCN≈110 ppm; 1J(Pt,13C)≈1425 Hz]. By contrast, complex [Pt(bzq)(C≡CPh)(CNXyl)] ( 4 ) with a trans‐Nbzq,CNR configuration, has been selectively isolated from [Pt(bzq)Cl(CNXyl)] (trans‐Nbzq,CNR) using Sonogashira conditions. X‐ray diffraction studies reveal that while 1 adopts a columnar‐stacked chain structure with Pt–Pt distances of 3.371(1) Å and significant π???π interactions (3.262 Å), complex 2 forms dimers supported only by short Pt???Pt (3.370(1) Å) interactions. In complex 4 the packing is directed by weak bzq???Xyl and bzq???C≡E (C, N) interactions. In solid state at room temperature, compounds 1 and 2 both show a bright red emission (?=42.1 % 1 , 57.6 % 2 ). Luminescence properties in the solid state at 77 K and concentration‐dependent emission studies in CH2Cl2 at 298 K and at 77 K are also reported for 1 , 1·CHCl3 , 2 , 2' , 2·CHCl3 , 3 , 4 . 相似文献
13.
Kazushi Mashima 《Macromolecular Symposia》2000,159(1):69-76
Half‐metallocene diene complexes of niobium and tantalum catalyzed three‐types of polymerization: (1) the living polymerization of ethylene by niobium and tantalum complexes, MCl2(η4‐1,3‐diene)(η5‐C5R5) ( 1‐4 ; M = Nb, Ta; R = H, Me) combined with an excess of methylaluminoxane; (2) the stereoselective ring opening metathesis polymerization of norbornene by bis(benzyl) tantalum complexes, Ta(CH2Ph)2(η4‐1,3‐butadiene)(η5‐C5R5) ( 11 : R = Me; 12 : R = H) and Ta(CH2Ph)2(η4‐o‐xylylene)(η5‐C5Me5) ( 16 ); and (3) the polymerization of methyl methacrylate by butadiene‐diazabutadiene complexes of tantalum, Ta(η2‐RN=CHCH=NR)(η4‐1,3‐butadiene)(η5‐C5Me5) ( 25 : R = p‐methoxyphenyl; 26 : R = cyclohexyl) in the presence of an aluminum compound ( 24 ) as an activator of the monomer. 相似文献
14.
《Polyhedron》1986,5(3):845-858
The complexes M(CO)4(R′-DAB) (M = Mo or W; R′-DAB = R′NCHCHNR′; R′ = i-Pr, t-Bu, Cy or p-tol) undergo substitution of a single CO ligand by isocyanide ligands RNC (R = Me, CHMe2, CMe3, C6H11 or xylyl), in refluxing toluene to give fac-M(CO)3(CNR)(R′-DAB). Synthesis of the latter complexes can also be achieved, at ambient temperature, through the use of the nitrile complexes, Mo(CO)3(NCMe)3 and W(CO)3(NCEt)3: the method involves substitution of the nitrile ligands first by R′-DAB, then by RNC. The intermediate compounds Mo(CO)3(NCMe)(R′-DAB) and W(CO)3(NCEt)(R′-DAB) have also been isolated and characterized. Oxidation of dark blue-purple Mo(CO)3(NCMe)(t-Bu-DAB) and Mo(CO)3(CNR)(t-Bu-DAB)(R = Me or CMe3) with [Cp2Fe]PF6 in dichloromethane solution produces the paramagnetic (17-electron), orange complexes [Mo(CO)3(NCMe)(t-Bu-DAB)PF6 and [Mo(CO)3(CNR)(t-Bu-DAB)]PF6, respectively. The molybdenum cations, [Mo(CO)3(NCMe)(t-Bu-DAB)]PF6 and [Mo(CO)3(CNCMe3)(t-Bu-DAB)]PF6, react with two and one equivalent of tert-butyl isocyanide, respectively, to yield dark red cis, trans-[Mo(CO)2(CNCMe3)2)t-Bu-DAB)]PF6. Reduction of cis, trans-[Mo(CO)2(CNCMe3)2)(t-Bu-DAB)]PF6 with cobaltocene in acetone yields the analogous dark blue zerovalent species cis, trans-Mo(CO)2(CNCMe3)2(t-Bu-DAB). The compounds [Mo(CO)(CNR)4(t-Bu-DAB)](PF6)2 and Mo(CO)3(CNR)(t-Bu-DAB) are produced, via a disproportionation reaction, when solutions of the cations [Mo(CO)3(CNR)(t-Bu-DAB)]+ (R = Me or CMe3) are reacted with ∼three equivalents of RNC. On the other hand, the reaction between tert-butyl isocyanide and [Mo(CO)3(CNCMe3)(i-Pr-DAB)]+ gives seven-coordinate [Mo(CNCMe3)5(i-Pr-DAB)](PF6)2 and Mo(CO)3(CNCMe3)(i-Pr-DAB). The ligand-based reduction of the complexes M(CO)3(CNR)(R′-DAB) (M = Mo or W) is readily accessible in THF upon addition of one molar equivalent of THF-soluble LiEt3BH to yield solutions that contain the radical anions [M(CO)3(CNR)(R′-DAB)]−.. The complexes synthesized in this work have been characterized on the basis of their spectroscopic and electrochemical properties, including ESR spectral studies on the paramagnetic 17- and 19-electron complexes. 相似文献
15.
《Journal of Coordination Chemistry》2012,65(5):776-780
Fe2(CO)9 and R2P(S)P(S)R2 (R = Et, n-Pr, n-Bu, Ph) react to form two types of cluster complexes Fe3(CO)9(μ3-S)2 (1), Fe2(CO)6(μ-SPR2)2 (2A)–(2D), [2A, R = Et; 2B, R = n-Pr; 2C, R = n-Bu; 2D, R = Ph]. The complexes result from phosphorus–phosphorus bond scission; in the former sulfur abstraction has also occurred. The complexes have been characterized by elemental analyses, FT-IR and 31P-[1H]-NMR spectroscopy and mass spectrometry. 相似文献
16.
Investigations on the Coordination Chemistry of Zinc Dialkyls. XIV. On Lithium and Zinc 3(N, N-Dialkylamino)propyl Compounds It is reported on synthesis and properties of organo lithium compounds of the type [R2NCH2CH2CH2Li]n. The structure is proposed by reason of molecular weight determination and 13C-NMR spectra. In dependence of the molar ratio the lithium dialkylamino propyls and the corresponding Grignard reagents react with zinc chloride forming dimer alkyl zinc chlorides [R2NCH2CH2CH2ZnCl]2 or monomer spiranoide chelate complexes of the formula [R2NCH2CH2CH2]2Zn (R = CH3, C2H5). 相似文献
17.
Hisashi Ōkawa Yuichiro Aratake Ken-Ichiro Motoda Masaaki Ohba Hiroshi Sakiyama Naohide Matsumoto 《Supramolecular chemistry》2013,25(3-4):293-302
Abstract Dinuclear Ni2(II,II) complexes with the formula [Ni2(Rm,n)](ClO4)2 ((m,n)= (2,2) (1), (2,3) (2), (2,4) (3)) have been obtained where (Rm,n)2- denotes the macrocycles containing two 2,6-bis(iminomethyl)-4-methylphenolate entities combined through two lateral chains, -(CH2)m- and -(CH2)n-, at the imino nitrogens. [Ni2(R2,2)](ClO4)2 (1) crystallizes in the triclinic crystal system, space group P 1, with Z=1, a=8.396(2) Å, b= 10.021(2) Å, c=8.104(2) Å, α=109.56(2)°, β=99.40(2)°, γ=79.89(2)°, V=628.5(3) Å3 and Z=1. The refinement converges with R=0.0384 and Rw=0.0415 for 2075 reflections with | Fo | > 3[sgrave](| Fo |). In the centrosymmetric [Ni2(R2,2)]2+, a pair of Ni(II) ions are bridged by two phenolic oxygens with the Ni···Ni separation of 2.801(1) Å. Each Ni assumes a planar configuration with Ni-O bond distances of 1.842(3) and 1.838(3) Å and Ni-N bond distances of 1.814(3) and 1.823(3) Å. In the solid state, 1 is diamagnetic (S1=S2=0) whereas [Ni2(R2,3)]-(ClO4)2 (2) and [Ni2(R2,4)](ClO4)2 (3) are of a mixed-spin (S1=0, S2=1). In DMSO and pyridine all the complexes assume high-spin (S1=S2=1). The Ni2(II,II) complexes are electrochemically reduced in DMSO or pyridine to Ni2(I,II) and Ni2(I,I) complexes. The conproportionation constants of the Ni2(I,II) complexes are determined to be 3.4X104-1.2X105 in DMSO and 1.6X103-2.6X105 in pyridine. The Ni2(I,II) and Ni2(I,I) complexes of 1–3 have been prepared by electrolysis in DMSO. The mixed-valent complexes of 1 and 2 are characterized by an intervalence (IV) transition band at 790 and ~ 700 nm, respectively, and belong to Class II using the classification of Robin and Day. The Ni2(I,II) complex of 3 shows no IT band (Class I). The Ni2(I,II) complexes of 1-3 show well-resolved ESR spectra due to the spin-coupled ST = 1/2 ground-state. The Ni2(I,I) complexes of 1-3 are all ESR- innocent probably due to the strong antiferromagnetic interaction. 相似文献
18.
Ernesto Carmona Margarita Paneque Manuel L. Poveda Robin D. Rogers Jerry L. Atwood 《Polyhedron》1984,3(3):317-323
The complex [NiCl2(PMe3)2] reacts with one equivalent of mg(CH2CMe3)Cl to yield the monoalkyl derivative trans-[Ni(CH2CMe3)Cl(PMe3)2], which can be carbonylated at room temperature and pressure to afford the acyl [Ni(COCH2CMe3)Cl(PMe3)2]. Other related alkyl and acyl complexes of composition [Ni(R)(NCS)(PMe3)2] (R = CH2CMe3, COCH2CMe3) and [Ni(R)(η-C5H5)L] (L = PMe3, R = CH2CMe3, COCH2CMe3; L = PPh3, R = CH2CMe2Ph) have been similarly prepared. Dialkyl derivatives [NiR2(dmpe)] (R = CH2SiMe3, CH2CMe2Ph; dmpe = 1,2-bis(dimethylphosphine)ethane, Me2PCH2 CH2PMe2) have been obtained by phosphine replacement of the labile pyridine and NNN′N′-tetramethylethylenediamine ligands in the corresponding [Ni(CH2SiMe3)2(py)2] and [Ni(CH2CMe2Ph)2(tmen)] complexes. A single-crystal X-ray determination carried out on the previously reported trimethylphosphine derivative [Ni(CH2SiMe3)2(PMe3)2] shows the complex belongs to the orthorhombic space group Pbcn, with a = 14.345(4), b = 12.656(3), c = 12.815(3) Å, Z = 4 and R 0.077 for 535 independent observed reflections. The phosphine ligands occupy mutually trans positions P-Ni-P 146.9(3)° in a distorted square-planar arrangement. 相似文献
19.
Metal Complexes of Biologically Important Ligands, CLVII [1] Halfsandwich Complexes of Isocyanoacetylamino acid esters and of Isocyanoacetyldi‐ and tripeptide esters (?Isocyanopeptides”?) N‐Isocyanoacetyl‐amino acid esters CNCH2C(O) NHCH(R)CO2CH3 (R = CH3, CH(CH3)2, CH2CH(CH3)2, CH2C6H5) and N‐isocyanoacetyl‐di‐ and tripeptide esters CNCH2C(O)NHCH(R1)C(O)NHCH(R2)CO2C2H5 and CNCH2C(O)NHCH(R1)C(O)NHCH (R2)C(O)NHCH(R3)CO2CH3 (R1 = R2 = R3 = CH2C6H5, R2 = H, CH2C6H5) are available by condensation of potassium isocyanoacetate with amino acid esters or peptide esters. These isocyanides form with chloro‐bridged complexes [(arene)M(Cl)(μ‐Cl)]2 (arene = Cp*, p‐cymene, M = Ir, Rh, Ru) in the presence of Ag[BF4] or Ag[CF3SO3] the cationic halfsandwich complexes [(arene)M(isocyanide)3]+X? (X = BF4, CF3SO3). 相似文献
20.
《Polyhedron》1988,7(18):1767-1771
The complexes [MOCl2(dmpe)(PMe3)] and [MOCl2(dmpe)2]Cl (M = Mo, W; dmpe = Me2PCH2CH2PMe2) have been prepared by reaction of the oxo compounds [MOCl2(PMe3)3] with equivalent amounts of the dmpe ligand under appropriate conditions. The dark blue tungsten species [WOCl2(dmpe)(PMe3)] forms only slowly but reacts readily with more dmpe to afford [WOCl(dmpe)2]Cl. This prevents isolation of the former in a pure form. The related isocyanide derivatives [MOCl2(CNR)(PMe3)2], (M = Mo; R = CMe3 and C6H11; M = W, R = CMe3) have been obtained similarly by reaction of the [MOCl2(PMe3)3] complexes with the stoichiometric amount of the isocyanide ligand, but attempts to prepare the carbonyl analogues, [MOCl2(CO)(PMe3)2], have proved unsuccessful. The new compounds have been characterized by analytical and spectroscopic methods (IR, 1H, 13C and 13P NMR spectroscopy). 相似文献