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1.
The present article describes design and synthesis of coumarin derived chemical reaction based chemodosimeter to recognize cyanide in aqueous medium. The Michael acceptor type coumarin derived probes 3 and 4 upon interaction with cyanide undergo Michael type nucleophilic addition reaction to form adducts in which fluorescence intensity was significantly enhanced, ‘turn-on’ by the change in intramolecular charge transfer (ICT) mechanism. The nonfluorescent color of solutions changed to a naked-eye sensitive fluorescent blue (switched-on). Job’s plot analysis revealed a 1:1 stoichiometry for the interaction between the probe and cyanide anion with a high detection limit. 相似文献
2.
Alexander Jakob 《Journal of organometallic chemistry》2008,693(26):3821-3830
In this work the synthesis of phosphane selenides (FcCC)nPh3−nPSe (2a, n = 1; 2b, n = 2; 2c, n = 3; Fc = ferrocenyl, (η5-C5H4)(η5-C5H5)Fe) from (FcCC)nPh3−nP (1a, n = 1; 1b, n = 2; 1c, n = 3) and selenium is described to estimate the σ-donor properties of these systems by 31P{1H} NMR spectroscopy. Progressive replacement of phenyl by ferrocenylethynyl causes a shielding of the phosphorus atom with increasing of the 1J(31P-77Se) coupling constants.The palladiumdichloride metal-organic complexes [((FcCC)nPh3−nP)2PdCl2] (3a, n = 1; 3b, n = 2; 3c, n = 3) have been used as (pre)catalysts in the Suzuki-Miyaura (reaction of 2-bromo-toluene (4a) and 4-bromo-acetophenone (4b), respectively, with phenyl boronic acid (5) to give 2-methyl biphenyl (6a) and 4-acetyl biphenyl (6b)) and in the Heck-Mizoroki reaction (treatment of iodobenzene (7) with tert-butyl acrylate (8) to give E-tert-butyl cinnamate (9)).The structures of molecules 1a, 1c, 2c, and 3c in the solid state were determined by single X-ray structure analysis showing that the structural parameters of these systems are unexceptional and correspond to those of related phosphanes, seleno phosphanes, and palladium dichloride complexes. 相似文献
3.
Son Thanh Phan 《Journal of organometallic chemistry》2006,691(4):604-610
Bis(dichlorosilyl)methanes 1 undergo the two kind reactions of a double hydrosilylation and a dehydrogenative double silylation with alkynes 2 such as acetylene and activated phenyl-substituted acetylenes in the presence of Speier’s catalyst to give 1,1,3,3-tetrachloro-1,3-disilacyclopentanes 3 and 1,1,3,3-tetrachloro-1,3-disilacyclopent-4-enes 4 as cyclic products, respectively, depending upon the molecular structures of both bis(dichlorosilyl)methanes (1) and alkynes (2). Simple bis(dichlorosilyl)methane (1a) reacted with alkynes [R1-CC-R2: R1 = H, R2 = H (2a), Ph (2b); R1 = R2 = Ph (2c)] at 80 °C to afford 1,1,3,3-tetrachloro-1,3-disilacyclopentanes 3 as the double hydrosilylation products in fair to good yields (33-84%). Among these reactions, the reaction with 2c gave a trans-4,5-diphenyl-1,1,3,3-tetrachloro-1,3-disilacyclopentane 3ac in the highest yield (84%). When a variety of bis(dichlorosilyl)(silyl)methanes [(MenCl3 − nSi)CH(SiHCl2)2: n = 0 (1b), 1 (1c), 2 (1d), 3 (1e)] were applied in the reaction with alkyne (2c) under the same reaction conditions. The double hydrosilylation products, 2-silyl-1,1,3,3-tetrachloro-1,3-disilacyclopentanes (3), were obtained in fair to excellent yields (38-98%). The yields of compound 3 deceased as follows: n = 1 > 2 > 3 > 0. The reaction of alkynes (2a-c) with 1c under the same conditions gave one of two type products of 1,1,3,3-tetrachloro-1,3-disilacyclopentanes 3 and 1,1,3,3-tetrachloro-1,3-disilacyclopent-4-enes (4): simple alkyne 2a and terminal 2b gave the latter products 4ca and 4cb in 91% and 57% yields, respectively, while internal alkyne 2c afforded the former cyclic products 3cc with trans form between two phenyl groups at the 3- and 4-carbon atoms in 98% yield, respectively. Among platinum compounds such as Speier’s catalyst, PtCl2(PEt3)2, Pt(PPh3)2(C2H4), Pt(PPh3)4, Pt[ViMeSiO]4, and Pt/C, Speier’s catalyst was the best catalyst for such silylation reactions. 相似文献
4.
Da Jung Kim Sang-deok Mun Sungwoo YoonChang Hwa Oh Hyoung-Ryun ParkTae-Soo You Junseong Lee Youngjo Kim 《Polyhedron》2011,30(6):1076-1079
Three monomeric boratranes B[(OCH2CH2)nN(CH2CMe2O)3−n] (n = 0, 1; n = 1, 2; n = 2, 3) have been synthesized by the reaction of B(OMe)3 with a series of triethanolateamines such as [(OCH2CH2)nN(CH2CMe2O)3−n]3− (n = 0, L1; n = 1, L2; n = 2, L3), where the number of CMe2 groups adjacent to the OH functionality varied from 3 (L1H3) to 2 (L2H3) to 1 (L3H3). These boratranes 1-3 have been characterized by solution 1H, 13C{1H} and 11B NMR, and the crystal structures of 1 and 2 have been determined by single crystal X-ray diffraction. 相似文献
5.
H.W. Peindy N’Dongo 《Journal of organometallic chemistry》2009,694(6):981-1500
We describe reactions of [99mTc(H2O)3(CO)3)]+ (1) with Diels-Alder products of cyclopentadiene such as “Thiele’s acid” (HCp-COOH)2 (2) and derivatives thereof in which the corresponding [(Cp-COOH)99mTc(CO)3)] (3) complex did form in water. We propose a metal mediated Diels-Alder reaction mechanism. To show that this reaction was not limited to carboxylate groups, we synthesized conjugates of 2 (HCp-CONHR)2 (4a-c) (4a, R = benzyl amine; 4b, R = Nα-Boc-l-2,3-diaminopropionic acid and 4c, R = glycine). The corresponding 99mTc complexes [(4a)99mTc(CO)3)] 6a, [(4b)99mTc(CO)3)] 6b and [(4c)99mTc(CO)3)] 6c have been prepared along the same route as for Thiele’s acid in aqueous media demonstrating the general applicability of this synthetic strategy. The authenticity of the 99mTc complexes on the no carrier added level have been confirmed by chromatographic comparison with the structurally characterized manganese or rhenium complexes.Studies of the reaction of 1 with Thiele’s acid bound to a solid phase resin demonstrated the formation of [(Cp-COOH)99mTc(CO)3)] 3 in a heterogeneous reaction. This is the first evidence for the formation of no carrier added 99mTc radiopharmaceuticals containing cyclopentadienyl ligands via solid phase syntheses. Macroscopically, the manganese analogue 5a and the rhenium complexes 5b-c have been prepared and characterized by IR, NMR, ESI-MS and X-ray crystallography for 5a (monoclinic, P21/c, a = 9.8696(2) Å, b = 25.8533(4) Å, c = 11.8414(2) Å, β = 98.7322(17)°) in order to unambiguously assign the authenticity of the corresponding 99mTc complexes. 相似文献
6.
Schiff base N,N′-bis(salicylidene)-p-phenylenediamine (LH2) complexed with Pt(en)Cl2 and Pd(en)Cl2 provided [Pt(en)L]2 · 4PF6 (1) and Pd(Salen) (2) (Salen = N,N′-bis(salicylidene)-ethylenediamine), respectively, which were characterized by their elemental analysis, spectroscopic data and X-ray data. A solid complex obtained by the reaction of hexafluorobenzene (hfb) with the representative complex 1 has been isolated and characterized as 3 (1 · hfb) using UV–Vis, NMR (1H, 13C and 19F) data. A solid complex of hfb with a reported Zn-cyclophane 4 has also been prepared and characterized 5 (4 · hfb) for comparison with complex 3. The association of hfb with 1 and 4 has also been monitored using UV–Vis and luminescence data. 相似文献
7.
Jung Hee MoonSo Han Kim Kang Mun LeeTae-Soo You Youngkyu DoYoungjo Kim 《Polyhedron》2011,30(13):2333-2338
Three monomeric germatranes, 1-isopropoxy-3,3,7,7,10,10-hexamethyl-2,8,9-trioxa-5-aza-1-germatricyclo[3.3.3.01,5]undecane (1), 1-isopropoxy-3,3,7,7-tetramethyl-2,8,9-trioxa-5-aza-1-germatricyclo[3.3.3.01,5]undecane (2), and 1-isopropoxy-3,3-dimethyl-2,8,9-trioxa-5-aza-1-germatricyclo[3.3.3.01,5]undecane (3) have been synthesized by the reaction of Ge(O-i-Pr)4 in refluxing toluene with corresponding triethanolamines, (HOCH2CH2)nN(CH2CMe2OH)3−n (n = 0, L1H3; n = 1, L2H3; n = 2, L3H3), where the number of CMe2 groups adjacent to a OH functionality varied from 3 (L1H3) to 2 (L2H3), and to 1 (L3H3). These germatranes 1-3 have been characterized by solution 1H and 13C{1H} NMR and the solid state structure of 2 has been determined by single crystal X-ray diffraction. 相似文献
8.
Anshu Singhal Dimple P. Dutta Shaikh M. Mobin Ingo Lieberwirth 《Journal of organometallic chemistry》2007,692(23):5285-5294
In an effort to find simple and common single-source precursors for palladium sulfide nanostructures, palladium(II) complexes, [Pd(S2X)2] (X = COMe (1), COiPr (2)) and η3-allylpalladium complexes with xanthate ligands, [(η3-CH2C(CH3)CR2)Pd(S2X)] (R = H, X = COMe (3); R = H, X = COEt (4); R = H, X = COiPr (5); R = CH3, X = COMe (6)), have been investigated. The crystal structures of [Pd(S2X)2] (X = COMe (1), CoiPr (2)) and [(η3-CH2C(CH3)CH2)Pd(S2COMe)] (3) have been established by single crystal X-ray diffraction analysis. The complexes, 1, 2 and 3 all contain a square planar palladium(II) centre. In the allyl complex 3, this is defined by the two sulfurs of the xanthate and the outer carbons of the 2-methylallyl ligand, while in the complexes, 1 and 2 it is defined by the four sulfur atoms of the xanthate ligand. Thermogravimetric studies have been carried out to evaluate the thermal stability of η3-allylpalladium(II) analogues. The complexes are useful precursors for the growth of nanocrystals of PdS either by furnace decomposition or solvothermolysis in dioctyl ether. The solvothermal decomposition of complexes in dioctyl ether gives a new metastable phase of PdS which can be transformed to the more stable tetragonal phase at 320 °C. The nanocrystals obtained have been characterized by PXRD, SEM, TEM and EDX. 相似文献
9.
Ching-Shiang Fang 《Journal of organometallic chemistry》2009,694(3):404-1617
Mononuclear complexes of the type, M(CO)4[Se2P(OR)2] (M = Mn, R = iPr, 1a; Et, 1b; M = Re, R = iPr, 3a; Et, 3b) can be prepared from either [-Se(Se)P(OiPr)2]2 (A) or [Se{-Se(Se)P(OEt)2}2] (B) with M(CO)5Br. O,O′-dialkyl diselenophosphate ([(RO)2PSe2]-, abbreviated as dsep) ligands generated from A and B act as a chelating ligand in these complexes. Upon refluxing in acetonitrile, these mononuclear complexes yield dinuclear complexes with a general formula of [M2(CO)6{Se2P(OR)2}2] (M = Mn, R = iPr, 2a; Et, 2b; M = Re, R = iPr, 4a; Et, 4b). Dsep ligands display a triconnective, bimetallic bonding mode in the dinuclear compounds and this kind of connective pattern has never been identified in any phosphor-1,1-diselenoato metal complexes. Compounds 2b, 3b, and 4 are structurally characterized. Compounds 2b and 3b display weak, secondary Se?Se interactions in their lattices. 相似文献
10.
A.F.M. Mustafizur Rahman Motoko Ishibashi 《Journal of organometallic chemistry》2004,689(21):3395-3401
Competitive chlorination of p-substituted triarylbismuthanes 1 [(p-XC6H4)3Bi; a: X = OMe, c: Cl, d: CO2Et, e: CF3, f: CN, g: NO2] and trimesitylbismuthane (2,4,6-Me3C6H2)3Bi 1h by sulfuryl chloride was carried out against 1b (X = H) and the effect of these substituents on the formation of triarylbismuth dichlorides 2 was studied. The relative ratios 2/2b decreased with increasing electron-withdrawing ability of the substituents (2a/2b = 53/47, 2c/2b = 33/67, 2d/2b = 35/65, 2e/2b = 29/71, 2f/2b = 16/84, 2g/2b = 0/100, 2h/2b = 46/54), indicating a lowering of reactivity of the lone pair on the bismuth atom. Pd-Catalyzed degradation of 2a-g and their difluorides 3 giving biaryls 4 was promoted by the electron-withdrawing p-substituents in the equatorial aryl groups but suppressed by the more electronegative fluorine atoms in the apical positions. This is in fairly good accord with the stability of the trigonal bipyramidal geometry. The 13C NMR study of 1-3 showed that the signals due to the ipso carbons (C1) attached to the bismuth atom shift downfield with increasing electron-withdrawing nature of the p-substituents. No such tendency was observed in other aromatic ring carbons. The electronic effect on the C1 atoms, similar to that on the chlorination of 1 and degradation of 2 and 3, indicates the significant participation of the C1 atoms in these reactions through the Bi-C1 bonds. 相似文献
11.
Dong Euy Jung 《Journal of organometallic chemistry》2011,696(23):3687-3692
The reaction of trichlorosilane (1a) at 250 °C with cycloalkenes, such as cyclopentene (2a), cyclohexene (2b), cycloheptene (2c), and cyclooctene (2d), gave cycloalkyltrichlorosilanes [CnH2n−1SiCl3: n = 5 (3a), 6 (3b), 7 (3c), 8 (3d)] within 6 h in excellent yields (97-98%), but the similar reactions using methyldichlorosilane (1b) instead of 1a required a longer reaction time of 40 h and afforded cycloalkyl(methyl)dichlorosilanes [CnH2n−1SiMeCl2: n = 5 (3e), 6 (3f), 7 (3g), 8 (3h)] in 88-92% yields with 4-8% recovery of reactant 2. In large (2, 0.29 mol)-scale preparations, the reactions of 2a and 2b with 1a (0.58 mol) under the same condition gave 3a and 3b in 95% and 94% isolated yields, respectively. The relative reactivity of four hydrosilanes [HSiCl3−mMem: m = 0-3] in the reaction with 2a indicates that as the number of chlorine-substituent(s) on the silicon increases the rate of the reaction decreases in the following order: n = 3 > 2 > 1 ? 0. In the reaction with 1a, the relative reactivity of four cycloalkenes (ring size = 5-8) decreases in the following order: 2d > 2a > 2c > 2b. Meanwhile linear alkenes like 1-hexene undergo two reactions of self-isomerization and hydrosilylation with hydrosilane to give a mixture of the three isomers (1-, 2-, and 3-silylated hexanes). In this reaction, the reactivity of the terminal 1-hexene is higher than the internal 2- and 3-hexene. The redistribution of hydrosilane 1 and the polymerization of olefin 2 occurred rarely under the thermal reaction condition. 相似文献
12.
Three new diorganotin(IV) complexes of the general formula R2Sn[3-(OMe)-2-OC6H3CHN-NC(O)Ph] (R = Ph, Ia; R = Me, Ib; R = n-Bu, Ic) have been synthesised from the corresponding diorganotin(IV) dichlorides and the ligand, N′-(2-hydroxy-3-methoxybenzylidene)benzohydrazide in methanol at room temperature in the presence of trimethylamine. All the complexes have been characterized by elemental analysis, IR and 1H, 13C, 15N, 119Sn NMR spectra, and their structures have been confirmed by single crystal X-ray diffraction analysis of one representative compound Ia. Complex Ia crystallises in the orthorhombic system, space group Pna21 with a = 12.424(5), b = 9.911(5), c = 18.872(5) Å; Z = 4. The ligand N′-(2-hydroxy-3-methoxybenzylidene)benzohydrazide (H2L) coordinates to the metal centre in the enolate form via the phenolic O, imino N and enolic O atoms. In Ia, the central tin atom adopts a distorted trigonal bipyramidal coordination geometry with the oxygen atoms in axial positions, while the imino nitrogen atom of the Schiff base and the two phenyl groups occupy the equatorial sites. The δ(119Sn) values for the complexes Ia, Ib and Ic are −327.3, −151.7 and −187.2 ppm, respectively, thus indicating penta-coordinated Sn centres in solution. 相似文献
13.
Nicolas Bréfuel Isabelle Vang Sergiu Shova Françoise Dahan Jean-Pierre Costes Jean-Pierre Tuchagues 《Polyhedron》2007
The synthesis and characterization of new symmetrical FeII complexes, [FeLA(NCS)2] (1), and [FeLBx(NCS)2] (2–4), are reported (LA is the tetradentate Schiff base N,N′-bis(1-pyridin-2-ylethylidene)-2,2-dimethylpropane-1,3-diamine, and LBx stands for the family of tetradentate Schiff bases N,N′-bis[(2-R-1H-imidazol-4-yl)methylene]-2,2-dimethylpropane-1,3-diamine, with: R = H for LB1 in 2, R = Me for LB2 in 3, and R = Ph for LB3 in 4). Single-crystal X-ray structures have been determined for 1 (low-spin state at 293 K), 2 (high-spin (HS) state at 200 K), and 3 (HS state at 180 K). These complexes remain in the same spin-state over the whole temperature range [80–400 K]. The dissymmetrical tetradentate Schiff base ligands LCx, N-[(2-R2-1H-imidazol-4-yl)methylene]-N′-(1-pyridin-2-ylethylidene)-2,2-R1-propane-1,3-diamine (R1 = H, Me; R2 = H, Me, Ph), containing both pyridine and imidazole rings were obtained as their [FeLCx(NCS)2] complexes, 5–10, through reaction of the isolated aminal type ligands 2-methyl-2-pyridin-2-ylhexahydropyrimidine (R1 = H, 5–7) or 2,5,5-trimethyl-2-pyridin-2-ylhexahydropyrimidine (R1 = Me, 8–10) with imidazole-4-carboxaldehyde (R2 = H: 5, 8), 2-methylimidazole-4-carboxaldehyde (R2 = Me: 6, 9), and 2-phenyl-imidazole-4-carboxaldehyde (R2 = Ph: 7, 10) in the presence of iron(II) thiocyanate. Together with the single-crystal X-ray structures of 7 and 9, variable-temperature magnetic susceptibility and Mössbauer studies of 5–10 showed that it is possible to tune the spin crossover properties in the [FeLCx(NCS)2] series by changing the 2-imidazole and/or C2-propylene susbtituent of LCx. 相似文献
14.
Fluorotitanates (LH)2[TiF6]·nH2O (1: R = pyridine, n = 1, 2: R = 2-picoline, n = 2, 3: R = 2,6-lutidine, n = 0, 4: R = 2,4,6-collidine, n = 0) and (LH)[TiF5(H2O)] (3a: L = 2,6-lutidine) have been synthesized by the reaction of pyridine or corresponding methyl substituted pyridines and titanium dioxide dissolved in hydrofluoric acid. The crystal structures of ionic compounds 1, 2, 3, 3a and 4 have been determined by single-crystal X-ray diffraction analysis. The hydrogen bonding led to the formation of discrete (LH)2[TiF6] units (4), chains (1-3), and layers (3a). The additional π-π interactions present in 1, 2, and 4 results in chain structures of 1 and 4 and in a layer structure of 2. The [TiF6]2− and [TiF5(H2O)]− anions were observed by 19F NMR spectroscopy in aqueous solutions of 1, 2, 3, 3a and 4. 相似文献
15.
The salts [S(NMe2)3][MF6] (M = Nb, 2a; M = Ta, 2b) and [S(NMe2)3][M2F11] (M = Nb, 2c; M = Ta, 2d) have been prepared by reacting MF5 (M = Nb, 1a; M = Ta, 1b) with [S(NMe2)3][SiMe3F2] (TASF reagent) in the appropriate molar ratio. The solid state structure of 2b has been ascertained by X-ray diffraction. The 1:1 molar ratio reactions of 1a with a variety of organic compounds (L) give the neutral adducts NbF5L [L = Me2CO, 3a; L = MeCHO, 3b; L = Ph2CO, 3c; L = tetrahydrofuran (thf), 3d; L = MeOH, 3e; L = EtOH, 3f; L = HOCH2CH2OMe, 3g; L = Ph3PO, 3h; L = NCMe, 3i] in good yields. The complexes MF5L [M = Nb, L = HCONMe2, 3j; M = Nb, L = (NMe2)2CO, 3k; M = Ta, L = (NMe2)2CO, 3l; M = Nb, L = OC(Me)CHCMe2, 3m] have been detected in solution in admixture with other unidentified products, upon 2:1 molar reaction of 1 with the appropriate reagent L. The ionic complexes [NbF4(tht)2][NbF6], 4a, and [NbF4(tht)2][Nb2F11], 4b, have been obtained by combination of tetrahydrothiophene (tht) and 1a, in 1:1 and 2:3 molar ratios, respectively. The treatment of 1 with a two-fold excess of L leads to the species [MF4L4][MF6] [M = Nb, L = HCONMe2, 5a; M = Ta, L = HCONMe2, 5b; M = Nb, L = thf, 5c; M = Ta, L = thf, 5d; M = Nb, L = OEt2, 5e]. The new complexes have been fully characterised by NMR spectroscopy. Moreover, the revised 19F NMR features of the known compounds MF5L [M = Ta, L = Me2CO, 3n; M = Ta, L = Ph2CO, 3o; M = Ta, L = MePhCO, 3p; M = Ta, L = thf, 3q; M = Nb, L = CH3CO2H, 3r; M = Nb, L = CH2ClCO2H, 3s; M = Ta, L = CH2ClCO2H, 3t], TaF4(acac), TaF4(Me-acac) and [TaF(Me-acac)3][TaF6] (Me-acac = methylacetylacetonato anion) are reported. 相似文献
16.
The synthesis, characterization and thermal behavior of new monomeric allylpalladium (II) complexes with dichalcogenoamidodiphosphinate anions are reported. The complexes [R = H, R′ = Pri, E = S (1a); R = H, R′ = Pri, E = Se (1b); R = H, R′ = Ph, E = S (1c); R = H, R′ = Ph, E = Se (1d); R = Me, R′ = Pri, E = S (2a); R = Me, R′ = Pri, E = Se (2b); R = Me, R′ = Ph, E = S (2c); R = Me, R′ = Ph, E = Se (2d)] have been prepared by room temperature reaction of [Pd(η3-CH2C(R)CH2)(acac)] (acac = acetylacetonate) with dichalcogenoimidodiphosphinic acids in acetonitrile solution. The complexes have been characterized by multinuclear NMR (1H, 13C{1H}, 31P{1H}, 77Se{1H}), FT-IR and elemental analyses. The crystal structures of complexes 1a, 1d and 2d have been reported and they consist of a six-membered PdE2P2N ring (E = S for 1a and Se for 1d and 2d) and an allyl group, C3H4R(R = H for 1a and 1d and Me for 2d). Thermogravimetric studies have been carried out for few representative complexes. The complexes thermally decompose in argon atmosphere to leave a residue of palladium chalcogenides, which have been characterized by PXRD, SEM and EDS. 相似文献
17.
Neutral η1-benzylnickel carbene complexes, [Ni(η1-CH2C6H5)(IiPr)(PMe3)(Cl)] (3) (IiPr = 1,3-bis-(2,6-diisopropylphenyl)imidazol-2-ylidene) and [Ni(η1-CH2C6H5)(SIiPr)(PMe3)(Cl)] (4) (SIiPr = 1,3-bis-(2,6-diisopropylphenyl)imidazolin-2-ylidene), were prepared by the reaction between [Ni(η3-CH2C6H5)(PMe3)(Cl)] and an equivalent amount of the corresponding free N-heterocyclic carbene. The preparation of η3-benzylnickel carbene complexes, [Ni(η3-CH2C6H5)(IiPr)(Cl)] (5) and [Ni(η3-CH2C6H5)(SIiPr)(Cl)] (6) were carried out by the abstraction of PMe3 from 3 and 4 by the treatment of B(C6F5)3. The treatment of AgX on 5 and 6 produced the anion-exchanged complexes, [Ni(η3-CH2C6H5)(NHC)(X)] (7, NHC = IiPr, X = O2CCF3; 8, NHC = IiPr, X = O3SCF3; 9, NHC = SIiPr, X = O2CCF3; 10, NHC = SIiPr, X = O3SCF3). The solid state structures of 3 and 10 were determined by X-ray crystallography. The η3-benzyl complexes of IiPr (5, 7, and 8) alone, in the absence of any activators such as borate and MAO, showed good catalytic activity towards the vinyl-type norbornene polymerization. The catalyst was thermally robust and the activity increases as the temperature rises to 130 °C. 相似文献
18.
Sergey Yu. Bylikin Vadim V. Negrebetsky Yuri E. Ovchinnikov Sergei V. Pestunovich Elena F. Belogolova Mikhail G. Voronkov Inna Kalikhman 《Journal of organometallic chemistry》2006,691(4):779-786
A general scheme of reactions between chloro(chloromethyl)dimethylstannane and N-trimethylsilylamides and -lactams was established by NMR and IR techniques. The reactions proceed via transmetallation followed by transformation of the N-stannylated intermediate (1) into (N-Sn)-coordinated O-stannylmethyl (2) and (O-Sn)-coordinated N-stannylmethyl (3) derivatives. In the cases of 2-piperidone and 2-hexahydroazepinone these products were isolated as individual compounds (2b,c and 3b,c). X-ray diffraction study of 1-(chlorodimethylstannylmethyl)-2-piperidone (3b) confirmed (3 + 2)-coordination state of the tin atom and axial positions of oxygen and halogen atoms. The experimental and quantum-chemically calculated structural parameters are discussed in comparison with those of related trigonal bipyramidal (TBP) silicon, germanium and tin derivatives. Calculation at the MP2/LanL2DZ/D95 level reveals that the stability of the (O-M)chelates increases in the following order: (O-Si) < (O-Ge) < (O-Sn). 相似文献
19.
Toru Isobe 《Journal of organometallic chemistry》2008,693(7):1225-1232
New o-phenylene-bridged tetrachalcogenoether ligands tethered with an extremely bulky substituent, 2,4,6-tris[bis(trimethylsilyl)methyl]phenyl (Tbt) group, [TbtE(o-phenylene)Se]2(o-phenylene) (3: E = S, 4: E = Se), were synthesized. Complexation reactions of 3 and 4 with Na2PdCl4 gave the corresponding dichloropalladium(II) complexes 7 and 8. X-ray structural analysis of 7 and 8 indicated that the central palladium metals are in a distorted octahedral environment, where the two inner selenium atoms and the two chlorine atoms form a square planar arrangement around the palladium metal and the two terminal chalcogen atoms weakly coordinate to the palladium center at the axial positions. The AIM calculations also supported the existence of the interaction between the palladium and the terminal chalcogen atoms in the crystalline state. On the other hand, the 77Se NMR spectra suggested that there are no or very weak interactions between the palladium and the terminal chalcogen atoms in solution. The UV/Vis spectra of 7, 8, and related compounds imply the possibility of weak interaction between the terminal selenium atoms and the palladium center in solution. 相似文献
20.
Simon J. Coles Michael B. Hursthouse ?ule ?ahin Aylin Uslu 《Journal of organometallic chemistry》2007,692(13):2811-2821
Derivatives of the tri-spirane pentaerythritoxy-cyclophosphazene compound 1 have been used to investigate the stereogenic properties of spiranes combined with either one or two conventional centres of chirality. In compound 1, the two inner rings are carbocyclic and symmetrical and the two outer rings are cyclotriphosphazenes substituted in different positions to provide the conventional centres of chirality. Reaction of 1 in a 1:1 molar ratio with the unsymmetrical dinucleophilic reagent, 1,3-aminopropanol, gave the mono-spiro substituted derivative 2, which was shown to exist as a racemate by X-ray crystallography and 31P NMR spectroscopy on addition of a chiral solvating agent (CSA). Reaction of 1 with 1,3-aminopropanol in a 1:2 molar ratio gave three diastereoisomeric di-mono-spiro products 3a-3c, which were all shown to be racemates using a combination of X-ray crystallography (3a, 3c) and 31P NMR spectroscopy on addition of a CSA (3b), thus proving the case of the stereogenic properties of spirane molecules combined with two equivalent conventional centres of chirality. It is also shown by quantitative 31P NMR spectroscopy of the reaction mixture and by isolation of reaction products that the proportions of the diastereoisomers 3a:3b:3c are in approximate ratios of 1:2:1, respectively, and these results have been rationalised by analysis of the stereogenic properties of the series of reactions 1 → 2 → 3. 相似文献