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1.
Fluorotitanates (LH)2[TiF6nH2O (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   

2.
The dipod 1,2-bis(8-quinolinoxymethyl)benzene 3 and tetrapod 1,2,4,5-tetrakis(8-quinolinoxymethyl)benzene 4 show two perturbations in fluorescence with Ag+, (i) fluorescence quenching with <1.0 equiv of AgNO3 at λmax 395 nm and (ii) fluorescence enhancement at λmax 500 nm with >3 equiv of AgNO3. This ‘ON-OFF-ON’ switching of 3 and 4 in comparison with simultaneous fluorescence quenching and enhancement in the case of 8-methoxyquinoline 1 and the tripod 1,3,5-trimethyl-2,4,6-tris(8-quinolinoxymethyl)benzene 2 point to the unique role of molecular architectures arising due to the number and spatial positions of quinoline units in the fluorescence behaviour of an 8-alkoxyquinoline moiety towards Ag+.  相似文献   

3.
Twelve new organotin complexes with 4-sulfanylbenzoic acid of two types: RnSn[S(C6H4COOH)]4−n (I) (n = 3: R = Me 1, n-Bu 2, Ph 3; PhCH24; n = 2: R = Me 5; n-Bu 6, Ph 7, PhCH28) and R3Sn(SC6H4COO)SnR3 · mEtOH (II) (m = 0: R = Me 9, n-Bu 10, PhCH212; m = 2: R = Ph 11), along with the 4,4′-bipy adduct of 9, [Me3Sn(SC6H4COO)SnMe3]2(4,4-bipy) 13, have been synthesized. The coordination behavior of 4-sulfanylbenzoic acid is monodentate in 1-8 by thiol S atom but not carboxylic oxygen atom. While, in 9-13 it behaves as multidenate by both thiol S atom and carboxylic oxygen atoms. The supramolecular structures of 6, 11 and 13 have been found to consist of 1D molecular chains built up by intermolecular O-H?O, C-H?O or C-H?S hydrogen bonds. The supramolecular aggregation of 7 is 2D network determined by two C-H?O hydrogen bonds. Extended intermolecular C-H?O interactions in the crystal lattice of 9 link the molecules into a 2D network.  相似文献   

4.
An efficient route to the novel tridentate phosphine ligands RP[CH2CH2CH2P(OR′)2]2 (I: R = Ph; R′ = i-Pr; II: R = Cy; R′ = i-Pr; III: R = Ph; R′ = Me and IV: R = Cy; R′ = Me) has been developed. The corresponding ruthenium and iron dicarbonyl complexes M(triphos)(CO)2 (1: M = Ru; triphos = I; 2: M = Ru; triphos = II; 3: M = Ru; triphos = III; 4: M = Ru; triphos = IV; 5: M = Fe; triphos = I; 6: M = Fe; triphos = II; 7: M = Fe; triphos = III and 8: M = Fe; triphos = IV) have been prepared and fully characterized. The structures of 1, 3 and 5 have been established by X-ray diffraction studies. The oxidative addition of MeI to 1-8 produces a mixture of the corresponding isomeric octahedral cationic complexes mer,trans-(13a-20a) and mer,cis-[M(Me)(triphos)(CO)2]I (13b-20b) (M = Ru, Fe; triphos = I-IV). The structures of 13a and 20a (as the tetraphenylborate salt (21)) have been verified by X-ray diffraction studies. The oxidative addition of other alkyl iodides (EtI, i-PrI and n-PrI) to 1-8 did not afford the corresponding alkyl metal complexes and rather the cationic octahedral iodo complexes mer,cis-[M(I)(triphos)(CO)2]I (22-29) (M = Ru, Fe; triphos = I-IV) were produced. Complexes 22-29 could also be obtained by the addition of a stoichiometric amount of I2 to 1-8. The structure of 22 has been verified by an X-ray diffraction study. Reaction of 13a/b-20a/b with CO afforded the acetyl complexes mer,trans-[M(COMe)(triphos)(CO)2]I, 30-37, respectively (M = Ru, Fe; triphos = I-IV). The ruthenium acetyl complexes 30-33 reacted slowly with 2-tert-butylimino-2-diethylamino-1,3-dimethylperhydro-1,3,2-diazaphosphorine (BEMP) even in boiling acetonitrile. Under the same conditions, the deprotonation reactions of the iron acetyl complexes 34-37 were completed within 24-40 h to afford the corresponding zero valent complexes 5-8. It was not possible to observe the intermediate ketene complexes. Tracing of the released ketene was attempted by deprotonation studies on the labelled species mer,trans-[Fe(COCD3)(triphos)(CO)2]I (38) and mer,trans-[Fe(13COMe)(triphos)(CO)2]I (39).  相似文献   

5.
A series of titanium complexes [(Ar)NC(CF3)CHC(R)O]2TiCl2 (4b: Ar = -C6H4OMe(p), R = Ph; 4c: Ar = -C6H4Me(p), R = Ph; 4d: Ar = -C6H4Me(o), R = Ph; 4e: Ar = α-Naphthyl, R = Ph; 4f: Ar = -C6H5, R = t-Bu; 4g: Ar = -C6H4OMe(p); R = t-Bu; 4h: Ar = -C6H4Me(p); R = t-Bu; 4i: Ar = -C6H4Me(o); R = t-Bu) has been synthesized and characterized. X-ray crystal structures reveal that complexes 4b, 4c and 4h adopt distorted octahedral geometry around the titanium center. With modified methylaluminoxane (MMAO) as a cocatalyst, complexes 4b-c and 4f-i are active catalysts for ethylene polymerization and ethylene/norbornene copolymerization, and produce high molecular weight polyethylenes and ethylene/norbornene alternating copolymers. In addition, the complex 4c/MMAO catalyst system exhibits the characteristics of a quasi-living copolymerization of ethylene and norbornene with narrow molecular weight distribution.  相似文献   

6.
The organotin (IV) derivatives of 2-mercapto-4-methylpyrimidine (Hmpymt) R3SnL (R = Ph 1, PhCH22, n-Bu 3), R2SnClmLn (m = 1, n = 1, R = CH34, Ph 5, n-Bu 6, PhCH27; m = 0, n = 2, R = CH38, n-Bu 9, Ph 10, PhCH211) were obtained by the reaction of the organotin(IV) chlorides R3SnCl or R2SnCl2 with 2-mercapto-4-methylpyrimidine hydrochloride (HCl · Hmpymt) in 1:1 or 1:2 molar ratio. All complexes 1-11 were characterized by elemental analyses, IR, 1H, 13C and temperature-dependent 119Sn NMR spectra. Except for complexes 3 and 6, the structures of complexes 1, 2, 4, 5, 7, 8-11 were confirmed by X-ray crystallography. Including tin-nitrogen intramolecular interaction, the tin atoms of complexes 1-7 are all five-coordinated and their geometries are distorted trigonal bipyramidal. While the tin atoms of complexes 8-11 are six-coordinated and their geometries are distorted octahedral. Besides, the ligand adopts the different coordination modes to bond to tin atom between the complexes 1, 6, 7 and 2, 3, 4, 5, 8-11. Furthermore, intermolecular Sn?N or Sn?S interactions were recognized in crystal structures of complexes 4, 7 and 11, respectively.  相似文献   

7.
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   

8.
A series of organotin (IV) complexes with 6-amino-1,3,5-triazine-2,4-dithiol of the type [(RnSnCl4−n)2 (C3H2N4S2)] (n = 3: R = Me 1, n-Bu 2, PhCH23, Ph 4; n = 2: R = Me 5, n-Bu 6, PhCH27, Ph 8) have been synthesized. All the complexes 1-8 have been characterized by elemental analysis, IR, 1H and 13C NMR spectra. Among them complexes 1, 4, 5 and 8 have also been characterized by X-ray crystallography diffraction analyses, which revealed that the tin atoms of complexes 1, 4, 5 and 8 are all five-coordinated with distorted trigonal bipyramid geometries.  相似文献   

9.
Six organotin compounds with 4,4′-thiodibenzenethiol (LH2) of the type RnSnL4−nSnRn (n = 3: R = Me 1, Ph 2, PhCH23, n = 2: R = Me 4, Ph 5, PhCH26) have been synthesized. All compounds were characterized by elemental analysis, IR and NMR (1H, 13C, and 119Sn) spectra. The structures of compounds 1, 2, 4, 5 and 6 were also determined by X-ray diffraction analysis, which revealed that compounds 1 and 2 were monomeric structures, compounds 4, 5 and 6 were centrosymmetric dinuclear macrocyclic structures, and all the tin(IV) atoms are four-coordinated. Furthermore, supramolecular structures were also found in compounds 1, 2, 4, 5 and 6, which exhibit one-dimensional chains, two-dimensional networks or three-dimensional structures through intermolecular C–H?S weak hydrogen bonds (WHBs), non-bonded Sn?S interactions or C–H?π interactions.  相似文献   

10.
A series of CH3COCo(CO)3L complexes (1, L = PCy3; 2, L = PMe2Ph; 3, L = PPh3; 4, L = P(para-F-Ph)3; 5, L = P(meta-F-Ph)3; and 6, L = P(ortho-tolyl)3) were studied as precatalyst for the title polymerization. The Co-P bond length primarily responds to the cone angle of the phosphine ligand (6 > 1 > 2 ≈ 3 ≈ 4 ≈ 5), while the back-donation to the axial acetyl ligand and the equatorial CO ligand depends on the electron-donating ability of the phosphine and increases in the order 1 > 6 > 2 > 3 > 4 > 5. The equilibrium constant for CH3COCo(CO)3L + CO ↔ CH3COCo(CO)4 + L depends on the electron-donating ability of the phosphine ligand except for 6 and follows the order 6 ? 5 > 4 > 3 > 2 > 1. The catalytic activity follows the order 6 > 5 > 4 > 3 > 1 > 2. The activity difference cannot be explained solely by the above equilibrium and is consistent with the competition for the acyl site by the phosphine as nucleophile against aziridine. The production of the β-lactam byproduct is attributed to catalyst decomposition, which is accelerated to the basicity/nucleophilicity of the phosphine ligand.  相似文献   

11.
2-Phenylaniline reacted with Pd(OAc)2 in toluene at room temperature for 24 h in a one-to-one molar ratio and with the system PdCl2, NaCl and NaOAc in a 1 (2-phenylaniline):1 (PdCl2):2 (NaCl):1 (NaOAc) molar ratio in methanol at room temperature for one week to give the dinuclear cyclopalladated compounds (μ-X)2[Pd{κ2-N2′,C1-2-(2′-NH2C6H4)C6H4}]2 [1a (X = OAc) and 1b (X = Cl)] in high yield. Moreover, the reaction between 2-phenylaniline and Pd(OAc)2 in one-to-one molar ratio in acid acetic at 60 °C for 4 h, followed by a metathesis reaction with LiBr, allowed isolation of the dinuclear cyclopalladated compound (μ-Br)2[Pd{κ2-N2′,C1-2-(2′-NH2C6H4)C6H4}]2 (1c) in moderate yield. A parallel treatment, but using monodeuterated acetic acid (DOAc) as solvent in the cyclopalladation reaction, allowed isolation of a mixture of compounds 1c, 1cd1 [Pd{κ2-N2′,C1-2-(2′-NH2C6H4)C6H4](μ-Br)2[Pd{κ2-N2′,C1-2-(2′-NH2C6H4)-3-d-C6H3] and 1cd2 (μ-Br)2[Pd{κ2-N2′,C1-2-(2′-NH2C6H4)-3-d-C6H3}]2 in moderate yield and with a deuterium content of ca. 60%. 1a and 1b reacted with pyridine and PPh3 affording the mononuclear cyclopalladated compounds [Pd{κ2-N2′,C1-2-(2′-NH2C6H4)C6H4}(X)(L)] [2a (X = OAc, L = py), 2b (X = Cl, L = py), 3a (X = OAc, L = PPh3) and 3b (X = Cl, L = PPh3)] in a yield from moderate to high. Furthermore, 1a reacted with Na(acac) · H2O to give the mononuclear cyclopalladated compound 4 [Pd{κ2-N2′,C1-2-(2′-NH2C6H4)C6H4}(acac)] in moderate yield. 1H NMR studies in CDCl3 solution of 2a, 2b, 3a, 3b and 4 showed that 2a and 3a presented an intramolecular hydrogen bond between the acetato ligand and the amino group, and were involved in a dynamic equilibrium with water present in the CDCl3 solvent; and that the enantiomeric molecules of 2b and 4 were in a fast exchange at room temperature, while they were in a slow exchange for 2a, 3a and 3b. The X-ray crystal structures of 3b and 4 were determined. 3b crystallized in the triclinic space group with a = 9.9170(10), b = 10.4750(10), c = 12.0890(10) Å, α = 98.610(10)°, β = 94.034(10)° and γ = 99.000(10)° and 4 in the monoclinic space group P21/a with a = 11.5900(10), b = 11.2730(10), c = 12.2150(10) Å, α = 90°, β = 107.6560(10)° and γ = 90°.  相似文献   

12.
The five new silanes C5Me3RSiMenCl3 − n (n = 3, R = i-Pr (5); n = 2, R = i-Pr (6); n = 2, R = s-Bu (7); n = 2, R = cyclohexyl (8); and n = 3, R = t-Bu (9)) were synthesized by reaction of 1-alkyl-2,3,4-trimethylcyclopentadienyl lithium salts with appropriate chlorosilane and characterized by NMR, MS, and IR spectra. At elevated temperatures (250-360 K), all the silanes undergo a non-degenerate sigmatropic silyl rearrangement, which generates non-equivalent structures a and b. The presence of minor structure c was observed in compounds 5 and 7 only. The Diels-Alder cycloaddition of 5 with strong dienophiles tetracyanoethylene (TCNE), and dimethylacetylenedicarboxylate (DMAD) provides compounds 10 and 11, which confirmed isomers a and b, respectively. The free energy of activation of b → a isomerization for compounds 5-8 evaluated from variable temperature NMR spectra show only marginal influence of group R on the 1,2-silyl shift rate. Moreover, in compounds 5 and 7, the process b → a was found significantly faster than b → c process in the above-mentioned temperature range.  相似文献   

13.
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   

14.
The 2-imino-1,10-phenanthroline ligands, 1,10-C12H7N2-2-CRN(2,6-i-Pr2-4-R1-C6H2) [R = R1 = H (L1); R = H, R1 = Br (L2); R = H, R1 = CN (L3); R = H, R1 = i-Pr (L4); R = Me, R1 = H (L5); R = Me, R1 = i-Pr (L6)], have been prepared in high yield from the condensation reaction of 1,10-C12H7N2-2-CRO (R = H, Me) with one equivalent of the corresponding 4-substituted 2,6-diisopropylaniline. The molecular structures of L2, L5 and L6 reveal the imino nitrogen atoms to adopt a transoid configuration with respect to the phenanthrolinyl nitrogen atoms. Treatment of Lx with one equivalent of CoCl2 in n-BuOH at 90 °C gives the high spin complexes, (Lx)CoCl2 [Lx = L1 (1a), L2 (1b), L3 (1c), L4 (1d), L5 (1e), L6 (1f)], in which the metal centres exhibit distorted square pyramidal geometries. Activation of 1a-1f with excess methylaluminoxane (MAO) gives catalysts that are modestly active for the oligomerisation of ethylene affording mainly linear α-olefins along with some degree of internal olefins. While the donor capability of the 4-position of the N-aryl group does not appear to affect the activity of the catalyst, it does have an influence on the ratio of α-olefins to internal olefins. Single crystal X-ray diffraction studies have been performed on L2, L5, L6, 1a, 1c and 1f.  相似文献   

15.
The reaction of Ni(OAc)2, NiX2 (X = Cl, Br) or CoCl2 with the proligand 2-amino-2-methyl-1,3-propanediol (ampdH2) affords a new family of tetranuclear complexes. The syntheses of [Ni4(OAc)4(ampdH)4] (1) and [M4X4(ampdH)4] (M = Ni, X = Cl, 2; M = Ni, X = Br, 3; M = Co, X = Cl, 4) are reported, together with the single crystal X-ray structures of 1, 2 and 4 and the magnetochemical characterization of 1, 3 and 4. Each member of this family of complexes displays a low symmetry structure that incorporates a {M4O4} core unit based on a distorted cubane. Magnetic measurements reveal ferromagnetic exchange interactions for 1, 3 and 4. These give rise to S = 4 ground state spins for the tetranuclear Ni complexes and an anisotropic effective S′ = 2 ground state for the Co complex.  相似文献   

16.
A new organometallic phosphanylalkene, 1-(diphenylphosphanyl)-1′-(dimethylvinylsilyl)ferrocene (2) was prepared and—together with 1-(diphenylphosphanyl)-1′-vinylferrocene (1)—studied as a ligand in iron- and tungsten-carbonyl complexes. The following complexes featuring the mentioned phosphanylalkenes as P-monodentate donors were isolated and characterised by spectral methods: [Fe(CO)4(L-κP)] (4, L = 1; 5, L = 2) and trans-[W(CO)4(L-κP)2] (6, L = 1; 7, L = 2). In addition, the solid-state structures of 4 and 6 have been determined by single-crystal X-ray diffraction and the electrochemical properties of compounds 1, 2, 4 and 6 were studied by cyclic voltammetry at platinum electrode.  相似文献   

17.
The reaction of acetonitrile (15) and mixed acetonitrile/water 1:1 (69) solutions containing the cyanide-bearing [Fe(bipy)(CN)4] building block (bipy = 2,2′-bipyridine) and the partially blocked [Ln(bpym)]3+ cation (Ln = lanthanide trivalent cation and bpym = 2,2′-bipyrimidine) has afforded two new families of 3d–4f supramolecular assemblies of formula [Ln(bpym)(NO3)2(H2O)3][Fe(bipy)(CN)4] · H2O · CH3CN [Ln = Sm (1), Gd (2), Tb (3), Dy (4) and Ho (5)] and [Ln(bpym)(NO3)2(H2O)4][Fe(bipy)(CN)4] [Ln = Pr (6), Nd (7), Sm (8), Gd (9)]. They crystallize in the P21/c (15) and P2/c (69) space groups and their structures are made up of [Fe(bipy)(CN)4] anions (19) and [Ln(bpym)(NO3)2(H2O)n]+ cations [n = 3 (15) and 4 (69)] with uncoordinated water and acetonitrile molecules (15) which are interlinked through an extensive network of hydrogen bonds and π–π stacking into three-dimensional motifs. Both families have in common the occurrence of the low-spin iron(III) unit [Fe(bipy)(CN)4] where two bipy–nitrogen and four cyanide–carbon atoms build a somewhat distorted octahedral surrounding around the iron atom [Fe–N = 1.980(3)–1.988(3) Å (15) and 1.988(2)–1.992(2) Å (69); Fe–C = 1.904(5)–1.952(4) Å (15) and 1.911(2)–1.948(3) Å (69)]. The main structural difference between both families concerns the environment of the lanthanide atom which is nine- (15)/10-coordinated (69) with a chelating bpym, two bidentate nitrate and three (15)/four (69) water molecules building distorted monocapped (15)/bicapped (69) square antiprisms. This different lanthanide environment is at the origin of the different hydrogen bonding pattern of the two families of compounds.  相似文献   

18.
N-Heterocyclic carbene ligands (NHC) were metalated with Pd(OAc)2 or [Ni(CH3CN)6](BF4)2 by in situ deprotonation of imidazolium salts to give the N-olefin functionalized biscarbene complexes [MX2(NHC)2] 3-7 (3: M = Pd, X = Br, NHC = 1,3-di(3-butenyl)imidazolin-2-ylidene; 4: M = Pd, X = Br, NHC = 1,3-di(4-pentenyl)imidazolin-2-ylidene; 5: M = Pd, X = I, NHC = 1,3-diallylimidazolin-2-ylidene; 6: M = Ni, X = I, NHC = 1,3-diallylimidazolin-2-ylidene; 7: M = Ni, X = I, NHC = 1-methyl-3-allylimidazolin-2-ylidene). Molecular structure determinations for 4-7 revealed that square-planar complexes with cis (5) or trans (4, 6, 7) coordination geometry at the metal center had been obtained. Reaction of nickelocene with imidazolium bromides afforded the η5-cyclopentadienyl (η5-Cp) monocarbene nickel complexes [NiBr(η5-Cp)(NHC)] 8 and 9 (8: NHC = 1-methyl-3-allylimidazolin-2-ylidene; 9: NHC = 1,3-diallylimidazolin-2-ylidene). The bromine abstraction in complexes 8 and 9 with silver tetrafluoroborate gave complexes [NiBr(η5-Cp)(η3-NHC)] 10 and 11. The X-ray structure analysis of 10 and 11 showed a trigonal-pyramidal coordination geometry at the nickel(II) center and coordination of one N-allyl substituent.  相似文献   

19.
A new fluorescent imidazolium-based cholestane receptor 4 bearing a pyrene moiety was synthesized. The binding ability of 4 toward various dicarboxylic acids was examined by UV-vis and fluorescence spectroscopy. Receptor 4 showed the highest binding constant for oxalic acid among all the tested dicarboxylic acids (Ka = 5.06 × 104 M−1). Oxalic acid formed a complex with 4 with a 1:2 ratio in ethanol.  相似文献   

20.
N-thioamide thiosemicarbazone derived from 4-(methylthio)benzaldehyde (R = H, HL1; R = Me, HL2 and R = Ph, HL3) have been prepared and their reaction with fac-[ReX(CO)3(CH3CN)2] (X = Br, Cl) in methanol gave the adducts [ReX(CO)3(HLn)] (1a X = Cl, n = 1; 1a′ X = Br, n = 1; 1b X = Cl, n = 2; 1b′ X = Br, n = 2; 1c X = Cl, n = 3; 1c′ X = Br, n = 3) in good yield.All the compounds have been characterized by elemental analysis, mass spectrometry (ESI), IR and 1H NMR spectroscopic methods. Moreover, the structures of HL2, HL3, HL3·(CH3)2SO and 1b′·H2O were also elucidated by X-ray diffraction. In 1b′, the rhenium atom is coordinated by the sulphur and the azomethine nitrogen atoms (κS,N3) forming a five-membered chelate ring, as well as three carbonyl and bromide ligands. The resulting coordination polyhedron can be described as a distorted octahedron.The structure of the dimers is based on rhenium(I) thiosemicarbazonates [Re2(L1)2(CO)6] (2a), [Re2(L2)2(CO)6] (2b) and [Re2(L3)2(CO)6] (2c) as determined by X-ray studies. Methods of synthesis were optimized to obtain amounts of these thiosemicarbazonate complexes. In these compounds the dimer structures are achieved by Re-S-Re bridges, where S is the thiolate sulphur from a κS,N3-bidentate thiosemicarbazonate ligand.Some single crystals isolated in the synthesis of 2b contain [Re(L4)(L2)(CO)3] (3b) where L4 (=2-methylamine-5-(para-methylsulfanephenyl)-1,3,4-thiadiazole) is originated in a cyclization process of the thiosemicarbazone. Furthermore, the rhenium atom is coordinate by the sulphur and the thioamidic nitrogen of the thiosemicarbazonate (κS,N2) affording a four-membered chelate ring.  相似文献   

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