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1.
The complexes of the type (ArCH2)2SnO were catalytic-oxygenated by Ag+ and yielded mixed-ligand organotin(IV) complexes (ArCH2)(2-C5H4NCO2)2(ArCOO)tin(IV) (Ar = C6H5 (1), 2-ClC6H4 (2), 2-CNC6H4 (3), 4-ClC6H4 (4), 4-CNC6H4 (5), 2-FC6H4 (6)). The complexes 1-6 are characterized by elemental analyses, IR and NMR (1H, 13C, 119Sn) spectroscopies. Single X-ray crystal structure analysis has been determined, which reveals that the center tin atom of complex 2 is seven-coordinated geometry. 相似文献
2.
Tsun-Hung Hsiao Tzu-Liang Wu Sandipan Chatterjee Chin-Yi Chiu Hon Man Lee Lorenzo Bettucci Claudio Bianchini Werner Oberhauser 《Journal of organometallic chemistry》2009,694(25):4014-4024
The imidazolium salts 1,1′-dibenzyl-3,3′-propylenediimidazolium dichloride and 1,1′-bis(1-naphthalenemethyl)-3,3′-propylenediimidazolium dichloride have been synthesized and transformed into the corresponding bis(NHC) ligands 1,1′-dibenzyl-3,3′-propylenediimidazol-2-ylidene (L1) and 1,1′-bis(1-naphthalenemethyl)-3,3′-propylenediimidazol-2-ylidene (L2) that have been employed to stabilize the PdII complexes PdCl2(κ2-C,C-L1) (2a) and PdCl2(κ2-C,C-L2) (2b). Both latter complexes together with their known homologous counterparts PdCl2(κ2-C,C-L3) (1a) (L3 = 1,1′-dibenzyl-3,3′-ethylenediimidazol-2-ylidene) and PdCl2(κ2-C,C-L4) (1b) (L4 = 1,1′-bis(1-naphthalenemethyl)-3,3′-ethylenediimidazol-2-ylidene) have been straightforwardly converted into the corresponding palladium acetate compounds Pd(κ1-O-OAc)2(κ2-C,C-L3) (3a) (OAc = acetate), Pd(κ1-O-OAc)2(κ2-C,C-L4) (3b), Pd(κ1-O-OAc)2(κ2-C,C-L1) (4a), and Pd(κ1-O-OAc)2(κ2-C,C-L2) (4b). In addition, the phosphanyl-NHC-modified palladium acetate complex Pd(κ1-O-OAc)2 (κ2-P,C-L5) (6) (L5 = 1-((2-diphenylphosphanyl)methylphenyl)-3-methyl-imidazol-2-ylidene) has been synthesized from corresponding palladium iodide complex PdI2(κ2-P,C-L5) (5). The reaction of the former complex with p-toluenesulfonic acid (p-TsOH) gave the corresponding bis-tosylate complex Pd(OTs)2(κ2-P,C-L5) (7). All new complexes have been characterized by multinuclear NMR spectroscopy and elemental analyses. In addition the solid-state structures of 1b·DMF, 2b·2DMF, 3a, 3b·DMF, 4a, 4b, and 6·CHCl3·2H2O have been determined by single crystal X-ray structure analyses. The palladium acetate complexes 3a/b, 4a/b, and 6 have been employed to catalyze the oxidative homocoupling reaction of terminal alkynes in acetonitrile chemoselectively yielding the corresponding 1,4-di-substituted 1,3-diyne in the presence of p-benzoquinone (BQ). The highest catalytic activity in the presence of BQ has been obtained with 6, while within the series of palladium-bis(NHC) complexes, 4b, featured with a n-propylene-bridge and the bulky N-1-naphthalenemethyl substituents, revealed as the most active compound. Hence, this latter precursor has been employed for analogous coupling reaction carried out in the presence of air pressure instead of BQ, yielding lower substrate conversion when compared to reaction performed in the presence of BQ. The important role of the ancillary ligand acetate in the course of the catalytic coupling reaction has been proved by variable-temperature NMR studies carried out with 6 and 7′ under catalytic reaction conditions. 相似文献
3.
Prakash C Srivastava Sangeeta BajpaiRoli Lath Chhabi RamSmriti Bajpai Ray J ButcherMichael Zimmer Michael Veith 《Journal of organometallic chemistry》2002,649(1):70-77
The reactions between R2TeI2 (R2=(CH3)2, C4H8, C5H10) and AgOCOR′ (R′=C6H5, 4-NO2C6H4, CHCHC6H5) (molar ratio 1:2) yield diorganotellurium dicarboxylates: (CH3)2Te(OCOC6H5)2 (1), C5H10 Te(OCOC6H5)2 (2), C4H8Te(OCO4-NO2C6H4)2 (3) and C4H8Te(OCOCHCHC6H5)2 (4). They are characterized by IR, (1H, 13C, 125Te) solution NMR; (13C, 125Te) solid state NMR spectroscopy. The X-ray structures of 1-4 (the immediate environment about tellurium is that of distorted trigonal bipyramidal geometry with a stereochemically active electron lone pair) are described in the context of their ability to generate intermolecular CH?O hydrogen bonds, which lead to the formation of supramolecular assemblies. 相似文献
4.
《Journal of organometallic chemistry》2003,665(1-2):76-86
The chloro-bridged dinuclear compound [{Pd[5-(COH)C6H3C(H)N(Cy)-C2,N]}(μ-Cl)]2 (1), reacts with tertiary diphosphines in 1:1 molar ratio to give [{Pd[5-(COH)C6H3C(H)NCy-C2,N](Cl)}2(μ-Ph2PRPPh2)] (R: CH2, 2; CH2CH2, 3; (CH2)4, 4; (CH2)6, 5; Fe(C5H4)2, 6; trans-CHCH, 7; C≡C, 8). Treatment of 1 with Ph2PCH2CH2AsPh2 (arphos) gives the dinuclear complex [{Pd[5-(COH)C6H3C(H)N(Cy)-C2,N](Cl)}2(μ-Ph2PCH2CH2AsPh2)] (9). The reaction of 1 with tertiary diphosphines or arphos in 1:2 molar ratio in the presence of NH4PF6 yields the mononuclear compounds [Pd{5-(COH)C6H3C(H)NCy-C2,N}(Ph2PRPPh2-P,P)][PF6] (R: (CH2)4, 10; (CH2)6, 11; Fe(C5H4)2, 12; 1,2-C6H4, 13; cis-CHCH, 14; NH, 15) and [Pd{5-(COH)C6H3C(H)N(Cy)-C2,N}(Ph2PCH2CH2AsPh2-P,As)][PF6] (16). 1H-, 31P-{1H}- and 13C-{1H}-NMR, IR and mass spectroscopic data are given. The crystal structures of compounds 3, 6, 9 and 16 have been determined by X-ray crystallography. 相似文献
5.
The Ni(II) complex of the Schiff base of (S)-N-(2-benzoyl-4-chlorophenyl)-1-benzylpyrrolidine-2-carboxamide and glycine (1) [GKCl] and the hemihydrate of the Ni(II) complex of the Schiff base of (S)-N-(2-benzoylphenyl)-1-benzylpyrrolidine-2-carboxamide and 2-aminoisobutiric acid (2) [Me2GK] were prepared and their absolute structures determined. The conformations of the complexes and their hydrogen bonding are discussed in detail. In complex 2, the repulsion between the benzyl group and an equatorial methyl group should affect the conformation of the benzyl group, distribution of the π-electron density in this group and distortion of the internal coordination sphere, while for complex 1, only minor conformational changes were expected. 1H and 13C NMR data for the 15N-labelled complex 2 were acquired and fully assigned in order to study the influence of π-electron density of the benzyl group to the long-range 13C–15N and 13C–13C spin–spin interactions. 相似文献
6.
《Journal of organometallic chemistry》1991,408(2):C25-C29
Upon warming the reaction mixture of Ni(cdt), C2F4, and 2,6-iPr2Ph-dad in THF from −78°C to room temperature the red-violet complex (2,6-iPr2Ph-dad)Ni(C2F4) (1) is obtained. 1 reacts with ethene already at −78°C by coupling of the olefinic ligands with the nickel atom to form the blue nickelatetrafluoro-cyclopentane compound (2,6-iPr2Ph-dad)Ni(C2H4C2F4) (2). 相似文献
7.
8.
Markus Henn Bernard Mahieu Arnaldo Cinquantini 《Journal of organometallic chemistry》2006,691(8):1560-1572
The intramolecularly coordinated heteroleptic stannylene [4-t-Bu-2,6-{P(O)(O-i-Pr)2}2C6H2]SnCl serves as synthon for the synthesis of the ferrocenyl-bridged bis(diorganostannylene) [4-t-Bu-2,6-{P(O)(O-i-Pr)2}2C6H2SnC5H4]2Fe (1) which in turn reacts with W(CO)6 and Cr(CO)4(C7H8) to provide the corresponding transition metal complexes [4-t-Bu-2,6-{P(O)(O-i-Pr)2}2C6H2Sn{W(CO)5}C5H4]2Fe (2) and [4-t-Bu-2,6-{P(O)(O-i-Pr)2}2C6H2SnC5H4]2Fe · Cr(CO)4 (3), respectively. Reaction of compound 1 with sulphur and atmospheric moisture gave, under partial tin-carbon and oxygen-carbon bond cleavage, a tetranuclear organotin-oxothio cluster 5. All compounds were characterized by 1H, 13C, 31P, and 119Sn NMR, and IR spectroscopy, as well as by single-crystal X-ray diffraction analysis. Compounds 1 and 3 were also investigated by Mössbauer spectroscopy. Cyclovoltametric studies reveal the influence of the organostannyl moieties on the redox-behaviour of compounds 1-3 in comparison with unsubstituted ferrocene. 相似文献
9.
Yuji Takashima 《Tetrahedron》2010,66(1):197-2519
A general approach to the (S)- and (R)-isoflavans was invented, and efficiency of the method was demonstrated by the synthesis of (S)-equol ((S)-3), (R)-sativan ((R)-4), and (R)-vestitol ((R)-5). The key step is the allylic substitution of (S)-6a (Ar1=2,4-(MeO)2C6H3) and (R)-6b (Ar1=2,4-(BnO)2C6H3) with copper reagents derived from CuBr·Me2S and Ar2-MgBr (7a, Ar2=4-MeOC6H4; 7b, 2,4-(MeO)2C6H3; 7c, 2-MOMO-4-MeOC6H3), furnishing anti SN2′ products (R)-8a and (S)-8b,c with 93-97% chirality transfer in 60-75% yields. The olefinic part of the products was oxidatively cleaved and the Me and Bn groups on the Ar1 moieties was then removed. Finally, phenol bromide 9a and phenol alcohols 9b,c underwent cyclization with K2CO3 and the Mitsunobu reagent to afford (S)-3 and (R)-4 and -5, respectively. 相似文献
10.
Yu. I. Slyvka A. V. Pavlyuk B. R. Ardan N. T. Pokhodilo E. A. Goreshnik P. Yu. Demchenko 《Russian Journal of Inorganic Chemistry》2012,57(6):815-821
Copper(I) ??-complexes of the compositions [Cu(C12H13N5O)(NO3)] · 0.5H2O (1) and [Cu(C12H13N5O)(CF3COO)] (2) (C12H13N5O is N-allyl-5-amino-1-phenyl-1H-1,2,3-triazole-4-carboxamide) were obtained by alternating-current electrochemical synthesis, and their crystal structures were studied by X-ray crystallography. Crystals of the compounds are monoclinic, space group C2/c with the unit cell parameters a = 21.3976(15) ?, b = 8.0335(4) ?, c = 18.6027(13) ?, ?? = 114.422(2)°, V = 2911.6(3) ?3, Z = 8 for 1; and a = 18.3578(18) ?, b = 9.8700(10) ?, c = 20.9094(18) ?, ?? = 106.883(3)°, V = 3625.3(6) ?3, Z = 8 for 2. In both structures, N-allyl-5-amino-1-phenyl-1H-1,2,3-triazole-4-carboxamide acts as a bridging tridentate chelating ligand and forms with copper(I) atoms infinite chains containing [CuC4NO] seven-membered rings. The chains are linked to form a three-dimensional framework due to hydrogen bonds (N)H??O, which involve nitrogen atoms of amino and amide groups of the ligand. The coordination sphere of Cu(I) atoms consists of olefin bond of the allyl C=C group, O atom of the carbonyl group, N(3) atom of the triazole nucleus of the organic ligand, and an oxygen atom of nitrate (compound 1) or trifluoroacetate (compound 2) anion, respectively. 相似文献
11.
Dafeng Du Chunling Liu Dongsheng Zhu Lin Xu 《Journal of organometallic chemistry》2011,696(13):2549-140
Six new organotin carboxylates based on 1,3-benzenedicarboxylic acid and 1,4-benzenedicarboxylic acid derivatives, namely (Ph3Sn)2(2,5-L1)(C2H5OH)2 (1) (2,5-H2L1 = 2,5-dibenzoylterephthalic acid), (Ph3Sn)2(2,5-L2)(C2H5OH)2 (2) (2,5-H2L2 = 2,5-bis(4-methylbenzoyl)terephthalic acid), (Ph3Sn)2(2,5-L3)(C2H5OH)2 (3) (2,5-H2L3 = 2,5-bis(4-ethylbenzoyl)terephthalic acid), [(n-Bu2Sn)4(4,6-L1)O2(OH)(OC2H5)]2·2(C2H5OH) (4) (4,6- H2L1 = 4,6-dibenzoylisophthalic acid), [(n-Bu2Sn)4(4,6-L1)O2(OH)(OC4H9)]2·2(C4H9OH) (5) and [(n-Bu2Sn)4(4,6-L2)O2(OH)(OC2H5)]2·2(C2H5OH) (6) (4,6-H2L2 = 4,6-bis(4-methylbenzoyl)isophthalic acid), have been synthesized. All the organotin carboxylates have been characterized by elemental analysis, IR, 1H and 13C NMR spectroscopy and X-ray crystallography diffraction analyses. The structural analysis reveals that complexes 1-3 show similar structures, containing binuclear triorganotin skeletons. The significant intermolecular O-H?O hydrogen bonds linked the complexes 1-3 to form a novel 2D network polymer with 38-member macrocycles. In complexes 4-6, two Sn4O4 ladders are connected by two 1,3-benzenedicarboxylic acid derivatives to yield ladder-like octanuclear architectures and form macrocycle with 24 atoms. In addition, the antitumor activities of complexes 1-6 have been studied. 相似文献
12.
《Journal of organometallic chemistry》1991,410(1):C13-C19
Reaction of 1,1′,3,3′-tetra-tert-butyl-5-′-pentafulvalenedipotassium (1) with hexacarbonylmolybdenum leads to hexacarbonyl-dipotassium(1,1′,3,′-tetra-tert-butyl-5,5′-pemtafulvalene)dimolybdate (2), which on further treatment with stoichiometric amounts of iodomethane yields the hexacarbonyldimethyl(1,1′-3,3′-tetra-tert-butyl-5,5′-pentafulvalene)dimolybdenum, (η5 : η5-tBu4C10H4)Mo2(CO)6-(CH)3)2 (3). Compound 3 is obtained as yellow needles and brownish cube-like crystals, and it is characterized by 1H-NMR, 13C-NMR, IR, and MS data. The cubes crystallize in the space group C2/c with four molecules in the unit cell. Each molecule consists of two tricarbonylmethyl(cyclopentadienyl) molybdenum units which are connected by a central CC-bond, twisted against each other by 64.8° and bent by 25.8°. Due to the steric requirements of the tertbutyl substituents in the fulvalene ligand, 3 should be formed only from cis-configurated 2. 相似文献
13.
Administration of 3,4-dihydroxyphenyl[2-14C] alanine to young Tylophora asthmatica plants revealed that ring B and carbon atoms C9 and C7 of tylophorine and tylophorinine are derived from dopa. Tracer experiments with 6,7-diphenylhexahydroindolizines (1–7) and (26) demonstrated that compound 1 is efficiently and specifically incorporated into tylophorine (13) and tylophorinine (16). Compounds (3), (4) and (26) were not metabolized by the plants to form (13) and (16) whereas (5) and (6) were utilized to yield (13) and (16). Compound (2) was very poorly converted into (13) and (16) and thus is not on the major biosynthetic pathway of (13) and (16). 相似文献
14.
15.
《Tetrahedron: Asymmetry》2000,11(13):2765-2779
The ligands 6-[(diphenylphosphanyl)methoxy]-4,8-di-tert-butyl-2,10-dimethoxy-5,7-dioxa-6-phosphadibenzo[a,c]cycloheptene, 1, (S)-4-[(diphenylphosphanyl)methoxy]-3,5-dioxa-4-phosphacyclohepta[2,1-a;3,4a′]dinaphthalene, (S)-2, and (S)-4-[(diphenylphosphanyl)methoxy]-2,6-bis-trimethylsilanyl-3,5-dioxa-4-phosphacyclohepta[2,1-a;3,4-a′]dinaphthalene, (S)-3, (S)-2-(3,5-dioxa-4-phosphacyclohepta[2,1-a;3,4-a′]dinaphthalen-4-yloxymethyl)pyridine, (S)-4, and (S)-2-(3,5-dioxa-4-phosphacyclohepta[2,1-a;3,4-a′]dinaphthalen-4-yloxy)pyridine, (S)-5, have been easily prepared.The cationic complexes [Pd(η3-C3H5)(L-L′)]CF3SO3 (L–L′=1–(S)-5) and [Pd(η3-PhCHCHCHPh)(L–L′)]CF3SO3 (L–L′=(S)-2–(S)-4) were synthesized by conventional methods starting from the complexes [Pd(η3-C3H5)Cl]2 and [Pd(η3-PhCHCHCHPh)Cl]2, respectively. The behavior in solution of all the π-allyl- and π-phenylallyl-(L–L′)palladium derivatives 6–14 was studied by 1H, 31P{1H}, 13C{1H} NMR and 2D-NOESY spectroscopy. As concerns the ligands (S)-4 and (S)-5, a satisfactory analysis of the structures in solution was possible only for palladium–allyl complexes [Pd(η3-C3H5)((S)-4)]CF3SO3, 11, and [Pd(η3-C3H5)((S)-5)]CF3SO3, 12, since the corresponding species [Pd(η3-PhCHCHCHPh)((S)-4)]CF3SO3, 13, and [Pd(η3-PhCHCHCHPh)((S)-5)]CF3SO3, 14, revealed low stability in solution for a long time. The new ligands (S)-2–(S)-5 were tested in the palladium-catalyzed enantioselective substitution of (1,3-diphenyl-1,2-propenyl)acetate by dimethylmalonate. The precatalyst [Pd(η3-C3H5)((S)-2)]CF3SO3 afforded the allyl substituted product in good yield (95%) and acceptable enantioselectivities (71% e.e. in the S form). A similar result was achieved with the precatalyst [Pd(η3-C3H5)((S)-3)]CF3SO3. The nucleophilic attack of the malonate occurred preferentially at allylic carbon far from the binaphthalene moiety, namely trans to the phosphite group. When the complexes containing ligands (S)-4 and (S)-5 were used as precatalysts, the product was obtained as a racemic mixture in high yield. The number of the configurational isomers of the Pd-allyl intermediates present in solution in the allylic alkylation and the relative concentrations are considered a determining factor for the enantioselectivity of the process. 相似文献
16.
Kota Thirumala Prasad Gajendra Gupta Anna Venkateswara Rao Babulal Das Kollipara Mohan Rao 《Polyhedron》2009,28(13):2649-2654
The mononuclear complexes [(η6-arene)Ru(ata)Cl]PF6 {ata = 2-acetylthiazole azine; arene = C6H6 [(1)PF6]; p-iPrC6H4Me [(2)PF6]; C6Me6 [(3)PF6]}, [(η5-C5Me5)M(ata)]PF6 {M = Rh [(4)PF6]; Ir [(5)PF6]} and [(η5-Cp)Ru(PPh3)2Cl] {η5-Cp = η5-C5H5 [(6)PF6]; η5-C5Me5 (Cp*) [(7)PF6]; η5-C9H7 (indenyl); [(8)PF6]} have been synthesised from the reaction of 2-acetylthiazole azine (ata) and the corresponding dimers [(η6-arene)Ru(μ-Cl)Cl]2, [(η5-C5Me5)M(μ-Cl)Cl]2, and [(η5-Cp)Ru(PPh3)2Cl], respectively. In addition to these complexes a hydrolysed product (9)PF6, was isolated from complex (4)PF6 in the process of crystallization. All these complexes are isolated as hexafluorophosphate salts and characterized by IR, NMR, mass spectrometry and UV–Vis spectroscopy. The molecular structures of [2]PF6 and [9]PF6 have been established by single-crystal X-ray structure analyses. 相似文献
17.
Qingzhi Zhang 《Tetrahedron》2009,65(25):4871-1607
An isotopically labelled building block, 2,3,4,6-tetra-O-acetyl-1-thio-β-d-[13C6]glucopyranose (4), is obtained from the commercially available [13C6]-d-glucose. This hexa-13C-labelled thioglucose can be employed to make any glucosinolate (8) for use as an internal standard for isotopic dilution LCMS analysis. Herein three typical glucosinolates in their hexa-13C-labelled form: [glucose-13C6]gluconasturtiin, [glucose-13C6]sinigrin and [glucose-13C6]glucoerucin are synthesised by coupling the isotopically labelled thioglucose (4) with the corresponding hydroximoyl chlorides followed by sulfation with pyridine sulfur trioxide and deacetylation with a catalytic amount of potassium methoxide, respectively. 相似文献
18.
Synthesis, characterization, and applications in Heck and Suzuki coupling reactions of amphiphilic cyclopalladated ferrocenylimines 总被引:1,自引:0,他引:1
Bing Mu Tiesheng Li Wenjian Xu Guoliang Zeng Pingping Liu Yangjie Wu 《Tetrahedron》2007,63(46):11475-11488
A series of novel amphiphilic ferrocenylimines and their cyclopalladated complexes of general formula [Fe(η5-C5H5)(η5-C5H4CR1NR2)] (R1=H, R2=C12H25-n4a, R1=H, R2=C16H33-n4b, R1=CH3, R2=C12H25-n4c, R1=CH3, R2=C16H33-n4d), [PdCl{[(η5-C5H5)]Fe[(η5-C5H3)CR1NR2]}]2 (5a-d), [PdCl{[(η5-C5H5)]Fe[(η5-C5H3)-CR1NR2]}(PPh3)] (6a-d), were prepared and characterized by 1H NMR, 13C NMR, 31P NMR, IR, HRMS, and elemental analysis. The crystal structures of 5c,d were determined by X-ray crystallography. These amphiphilic cyclopalladated complexes are thermally stable and insensitive to oxygen and moisture. The redox properties of 4a-d, 5a-d, 6a-d were also investigated using cyclic voltammetric technique. Compounds 5a-d, 6a-d displayed good activity in the Heck reaction of a variety of aryl halides with ethyl acrylate or styrene and the Suzuki-Miyaura cross-coupling reaction of aryl bromides with phenylboronic acid in bulk solution. They are also suitable for formation of Langmuir-Blodgett (LB) films. 相似文献
19.
A series of ansa-metallocene complexes with an allyl substituted silane bridge [(CH2CHCH2)CH3Si(C5H4)2]TiCl2 (1), [(CH2CHCH2)CH3Si(C9H6)2]MCl2 [M=Ti (2), Zr (3), Hf (4)] and [(CH2CHCH2)CH3Si(C13H8)2]ZrCl2 (6) have been synthesized and characterized. The molecular structure of 6 has been determined by X-ray crystallographic analysis. Complexes 1-4, 6 bearing allyl groups have been investigated as self-immobilized catalysts for ethylene polymerization in the presence of MMAO. The results showed that the self-immobilized catalysts 1-4, 6 kept high ethylene polymerization activities of ca. 106 g PE mol−1 M h−1 and high molecular weight (Mw≈105) of polyethylene. 相似文献
20.
Cheng Zhang 《Journal of organometallic chemistry》2008,693(19):3151-3158
A series of aluminum and zinc complexes supported by functionalized phenolate ligands were synthesized and characterized. Reaction of 2-(3,5-R2C3N2)C6H4NH2 (R = Me, Ph) with salicylaldehyde or 3,5-di-tert-butylsalicylaldehyde afforded 2-((2-(1H-pyrazol-1-yl)phenylimino)methyl)phenol derivatives 2a-2d. Treatment of 2a-2d with an equiv. of AlR23 (R2 = Me, Et) gave corresponding aluminum aryloxides 3a-3e, while reaction with an equiv. of ZnEt2 afforded zinc aryloxides 4a-4d. Treatment of 2c with 0.5 equiv. of ZnEt2 formed diphenolato zinc complex 5. All new compounds were characterized by 1H and 13C NMR spectroscopy and elemental analyses. The structures of complexes 3a, 4a and 5 were further characterized by single crystal X-ray diffraction techniques. The catalytic activity of complexes 3-5 toward the ring-opening polymerization of ε-caprolactone was studied. The zinc complexes (4a-4d) exhibited higher catalytic activity than the aluminum complexes (3a-3e). The diphenolato zinc complex 5 showed lower catalytic activity than the ethylzinc complexes 4a-4d. The aluminum complex (3b) is inactive to initiate the ROP of rac-lactide, while the zinc complex (4d) is active initiator for the ROP of rac-lactide, giving atactic polylactide. 相似文献