共查询到20条相似文献,搜索用时 15 毫秒
1.
Cristiano Zuccaccia Gianfranco Bellachioma Giuseppe Cardaci Alceo Macchioni Barbara Binotti Carla Carfagna 《Helvetica chimica acta》2006,89(8):1524-1546
Palladacyclic compounds [Pd(C6H4(C6H5C?O)C?N? R)(N? N)] [X] (R = Et, iPr, 2,6‐iPr2C6H3; N? N = bpy = 2,2′‐bipyridine, or 1,4‐(o,o′‐dialkylaryl)‐1,4‐diazabuta‐1,3‐dienes; [X]? = [BF4]? or [PF6]?) were synthesized from the dimers [{Pd(C6H4(C6H5C?O)C?N? R)(μ‐Cl)}2] and N? N ligands. Their interionic structure in CD2Cl2 was determined by means of 19F,1H‐HOESY experiments and compared with that in the solid state derived from X‐ray single‐crystal studies. [Pd(C6H4(C6H5C?O)C?N? R)(N? N)] [X] complexes were found to copolymerize CO and p‐methylstyrene affording syndiotactic or isotactic copolymers when bpy or 1,4‐(o,o′‐dimethylaryl)‐1,4‐diazabuta‐1,3‐dienes were used, respectively. The reactions with CO and p‐methylstyrene of the bpy derivatives were investigated. Two intermediates derived from a single and a double insertion of CO into the Pd? C bonds were isolated and completely characterized in solution. 相似文献
2.
Mahmoud Sunjuk Mousa Al‐Noaimi Yahya Al‐Degs Tareq Al‐Qirem Ekkehard Lindner Adnan S. Abu‐Surrah 《Journal of polymer science. Part A, Polymer chemistry》2009,47(23):6715-6725
Water‐soluble palladium complexes cis‐[Pd(L)(OAc)2] ( 1–8 ) (L represents a diphosphine ligands of the general formula CH2(CH2PR2)2, where for a : R ? (CH2)6OH; b–g : R ? (CH2)nP(O)(OEt)2, n = 2–6 and n = 8; h : R ? (CH2)3NH2) have been employed, after activation with a large excess of HBF4, for emulsion polymerization of alkenes (propene, butene, and their equimolar mixtures) with carbon monoxide. Aliphatic polyketone lattices with a high solid content (21%), high molecular weight (6.3 × 104 g mol?1), and narrow polydispersities (Mw/Mn ≈ 2) were isolated. The catalytic activity of the dicationic palladium (II) based catalysts, C1–C8 is highly dependent on the length of the alkyl chain of the ligand. Catalyst 3 proved to be highly active for propene/CO copolymers, whereas 6 is active for butene/CO and propene/CO‐butene/CO systems. The presence of methyl β‐cyclodextrin, as a phase‐transfer agent, and undecenoic acid, as an emulsifier, increase the molar mass and the stability of the polyketones and finally the activity of the catalyst. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6715–6725, 2009 相似文献
3.
Yulin Han Yichuan Zhao Prof. Dr. Shengming Ma 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(40):9529-9533
An efficient chirality transfer in the [RhCl(CO)2]2-catalyzed [2+2+1] cyclization of optically active axially chiral 1,3-disubstituted allenynes with CO to access optically active bicyclopentenone compounds has been developed. The distal C=C bond of allenes reacted with the alknye unit and CO to afford [4.3.0]-bicyclic products with high ee values under mild reaction conditions with an excellent selectivity. 相似文献
4.
Xiang Ru Xianghua Zeng Zhimei Li David J. Evans Caixia Zhan Ying Tang Lianjie Wang Xiaoming Liu 《Journal of polymer science. Part A, Polymer chemistry》2010,48(11):2410-2417
A complex pendant with two ethynyl groups, [Fe2(μ‐SCH2CCH)2(CO)6] ( 2 ), as a model of the diiron subunit of [FeFe]‐hydrogenase was polymerized and the {Fe2(CO)6} core was successfully incorporated into the polymer matrix. The polymer was characterized by a variety of spectroscopic techniques, TGA, FTIR, SEM, TEM, and NMR. The resultant polymer was immobilized via “click” chemistry using its terminal C?CH bond onto the surface of a gold electrode, which was premodified with azidothiol by self‐assembled monolayer (SAM). The assembled electrode showed electrochemical responses. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2410–2417, 2010 相似文献
5.
Gwang‐Su Byun Sang Youl Kim Iwhan Cho 《Journal of polymer science. Part A, Polymer chemistry》2006,44(3):1263-1270
(?)‐(1S,2R)‐Norbornene‐2‐carboxylic acid alkyl esters (alkyl = Me, Bz, L ‐menthyl, or D ‐menthyl) were successfully prepared by the Diels–Alder reaction of cyclopentadiene with (R)‐(?)‐pantolactone‐O‐yl acrylate followed by epimerization and column chromatography. The enantiomeric excess was 99.9%. These monomers were polymerized by Pd(II)‐based catalysts, and high yields of the polymers were obtained. The methyl ester gave an optically active polymer of high optical rotation (monomer [α]D = ?24.7, polymer [α]D = ?98.5). This high rotation value of the polymer was attributed to the isotactic chain regulation of the polymer. This high rotation was not observed with methyl esters prepared by the transesterification of menthyl esters. The stereoregular polymer exhibited notable resonance peaks at 39 ppm in 13C NMR spectra. No crystallinity was observed. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1263–1270, 2006 相似文献
6.
Dr. Ulrich F. J. Mayer Elliot Murphy Dr. Mairi F. Haddow Prof. Michael Green Prof. Roger W. Alder Prof. Duncan F. Wass 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(13):4287-4299
We make the case for benzo[c]quinolin‐6‐ylidene ( 1 ) as a strongly electron‐donating carbene ligand. The facile synthesis of 6‐trifluoromethanesulfonylbenzo[c]quinolizinium trifluoromethanesulfonate ( 2 ) gives straightforward access to a useful precursor for oxidative addition to low‐valent metals, to yield the desired carbene complexes. This concept has been achieved in the case of [Mn(benzo[c]quinolin‐6‐ylidene)(CO)5]+ ( 15 ) and [Pd(benzo[c]quinolin‐6‐ylidene)(PPh3)2(L)]2+ L=THF ( 21 ), OTf ( 22 ) or pyridine ( 23 ). Attempts to coordinate to nickel result in coupling products from two carbene precursor fragments. The CO IR‐stretching‐frequency data for the manganese compound suggests benzo[c]quinolin‐6‐ylidene is at least as strong a donor as any heteroatom‐stabilised carbene ligand reported. 相似文献
7.
Scott J. Moravek Jamie M. Messman Robson F. Storey 《Journal of polymer science. Part A, Polymer chemistry》2009,47(3):797-803
rac‐Lactide polymerization kinetics in THF at 72 °C were monitored in real‐time using mid‐infrared ATR‐FTIR spectroscopy, with diamond composite insertion probe and light conduit technology. Monomer concentration as a function of time was acquired using the 1240 cm?1 resonance associated with the ? CO? O? C? stretch. Polymerizations were initiated with either n‐propanol (PrOH), ethylene glycol (EG), trimethylol propane (TMP), or pentaerythritol (PENTA) with the coinitiator stannous octoate (Sn(Oct)2). Polymerizations were found to be reversible at high monomer conversions, with a residual monomer concentration at 72 °C (345 K) of 0.081 M. The polymerizations were internally first‐order with respect to monomer, indicating a constant concentration of propagating centers. For a typical reaction with [rac‐LA]0 = 1.0 M, [PENTA]0 = 1.3 × 10?2 M, and [Sn(Oct)2] = 2.5 × 10?2 M, the first‐order rate constant, kapp was measured as 1.8 × 10?4 s?1. First‐order rate constants were determined to be independent of polymer architecture (i.e., initiator functionality) and proportional to [Sn(Oct)2] for [Sn(Oct)2]0/[ROH]0 ? 1, where [ROH]0 represents the initial concentration of initiating hydroxyl groups. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 797–803, 2009 相似文献
8.
Synthesis,characterization, and metal complexes of polyacetylenes with pendant 2,2′‐bipyridyl groups
Jos Vicente Juan Gil‐Rubio Natalia Barquero 《Journal of polymer science. Part A, Polymer chemistry》2005,43(14):3167-3177
5‐Ethynyl‐2,2′‐bipyridine ( 1 ; bpyC≡CH) polymerized in the presence of catalytic amounts of [RhF(COD)(PPh3)] or [Rh(μ‐OH)(COD)]2 (COD = 1,5‐cyclooctadiene) in 74–91% yields. In contrast, [Rh(μ‐X)(NBD)]2 (X = Cl or OMe; NBD = norbornadiene) did not catalyze the polymerization of 1 or gave low yields of the polymer. The obtained polymer, poly(5‐ethynyl‐2,2′‐bipyridine) [ 2 ; (bpyC?CH)n], was highly stereoregular with a predominant cis–transoidal geometry. Random copolyacetylenes containing the 2,2′‐bipyridyl group with improved solubility in organic solvents were obtained by the treatment of a mixture of 1 and phenylacetylene ( 3 ) or 1‐ethynyl‐4‐n‐pentyl‐benzene with catalytic amounts of [RhF(COD)(PPh3)]. A block copolymer of 1 and 3 was prepared by the addition of 1 to a poly(phenylacetylene) containing a living end. The reaction of 2 with [Mo(CO)6] produced an insoluble polymer containing [Mo(CO)4(bpy)] groups, whereas with [RuCl2(bpy)2] or [Ru(bpy)2(CH3COCH3)2](CF3SO3)2, it gave soluble metal–polymer complexes containing [Ru(bpy)3]2+ groups. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43:3167–3177, 2005 相似文献
9.
Shi‐Meng Wang Xiao‐Yan Wang Prof. Dr. Hua‐Li Qin Prof. Dr. Cheng‐Pan Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(19):6542-6546
A Pd‐catalyzed Suzuki cross‐coupling of arylboronic acids with Yagupolskii–Umemoto reagents was explored. In contrary to trifluoromethylations, the Pd‐catalyzed reaction of R?B(OH)2 and [Ar2SCF3]+[OTf]? provided the arylation products (R?Ar) in good to high yields. The reaction confirms that the S?Ar bonds of [Ar2SCF3]+[OTf]? can be readily cleaved in the presence of Pd complexes. The relatively electron‐poor aryl groups of asymmetric [Ar1Ar2SCF3]+[OTf]? salts are more favorably transferred compared to the electron‐rich ones. This reaction represents the first report of utilization of [Ar2SCF3]+[OTf]? as arylation reagents in organic synthesis. 相似文献
10.
A diiron hexacarbonyl complex containing bridging phenanthrene‐4,5‐dithiolate ligand is prepared by oxidative addition of Phenanthro[4,5‐cde][1,2]dithiin to Fe2(CO)9. The complex is investigated as a model for the active site of the [Fe–Fe] hydrogenase enzyme. The compound, [(μ‐PNT)Fe2(CO)6]; (PNT = phenanthrene‐4,5‐dithiolate), was characterized by spectroscopic methods (IR, UV/Vis and NMR) and X‐ray crystallography. The IR and proton NMR spectra of [(μ‐PNT)Fe2(CO)6] ( 4 ) are in agreement with a PNT ligand attached to a Fe2(CO)6 core. The infrared spectrum of 4 recorded in dichloromethane contains three peaks at 2001, 2040, and 2075 cm–1 corresponding to the stretching frequency of terminal metal carbonyls. X‐ray crystallographic study unequivocally confirms the structure of the complex having a butterfly shape with an Fe–Fe bond length of 2.5365 Å close to that of the enzyme (2.6 Å). Electrochemical properties of [(μ‐PNT)Fe2(CO)6] have been investigated by cyclic voltammetry. The cyclic voltammogram of [(μ‐PNT)Fe2(CO)6] recorded in acetonitrile contains one quasi‐irreversible reduction (E1/2 = –0.84 V vs. Ag/AgCl, Ipc/Ipa = 0.6, ΔEp = 131 V at 0.1 V · s–1) and one irreversible oxidation (Epa = 0.86 V vs. Ag/AgCl). The redox of [(μ‐PNT)Fe2(CO)6] at E1/2 = –0.84 V can be assigned to the one‐electron transfer processes; [FeI–FeI] → [FeI–Fe0] and [FeI–Fe0] → [FeI–FeI]. 相似文献
11.
Prof. Dr. Wolfram W. Seidel Woldemar Dachtler Julia Semmler Marco Tänzler Manuel Folk Dr. Alexander Villinger 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(43):14702-14711
A series of heterodinuclear complexes with acetylene dithiolate (acdt2?) as the bridging moiety were synthesised by a facile one‐pot procedure that avoided use of the highly elusive acetylene dithiol. Generation of the W–Ru complex [Tp′W(CN)(CO)(C2S2)Ru(η5‐C5H5)(PPh3)] (Tp’=hydrotris(3,5‐dimethylpyrazolyl)borate) and the W–Pd complexes [Tp′W(CN)(CO)(C2S2)Pd(dppe)] and [Tp′W(CO)2(C2S2)Pd(dppe)][PF6] (dppe=1,2‐bis(diphenylphoshino)ethane), which exhibit a [W(η2‐κ2‐C2S2)M] core (M=Ru, Pd), was accomplished by using a transition‐metal‐assisted solvolytical removal of the Me3Si‐ethyl thiol protecting groups. All intermediate species of the reaction have been fully characterised. The highly coloured W–Ru complex [Tp′W(CN)(CO)(C2S2)Ru(η5‐C5H5)(PPh3)] shows reversible redox chemistry, as does the prototype complex [Tp′W(CO)2(C2S2)Ru(η5‐C5H5)(PPh3)][PF6]. Single crystal X‐ray diffraction and IR, EPR and UV/Vis spectroscopic studies in conjunction with DFT calculations prove the high electronic delocalisation of states over the acdt2? linker. Comparative studies revealed a higher donor strength and more pronounced dithiolate character of acdt2? in [Tp′W(CN)(CO)(C2S2)Ru(η5‐C5H5)(PPh3)] relative to [Tp′W(CO)2(C2S2)Ru(η5‐C5H5)(PPh3)]+. In addition, the influence of the overall complex charge on the metric parameters was investigated by single‐crystal X‐ray diffraction studies with the W–Pd complexes [Tp′WL2(C2S2)Pd(dppe)] (L=(CN?)(CO) or (CO)2). The central [W(C2S2)Pd] units exhibit high structural similarity, which indicates the extensive delocalisation of charge over both metals. 相似文献
12.
Silvia Suárez‐Suárez Prof. Gabino A. Carriedo Dr. Alejandro Presa Soto 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(47):15933-15940
We describe a new and very versatile method to place chosen chemical functionalities at the edge of the pores of macroporous materials. The method is based on the synthesis and self‐assembly of inorganic block copolymers (BCPs) having chiral rigid segments bearing controllable quantities of randomly distributed functional groups. The synthesis of a series of optically active block copolyphosphazenes (PP) with the general formula [N?P(R‐O2C20H12)0.9(FG)0.2]n‐b‐[N?PMePh]m (FG=‐OC5H4N ( 6 ), ‐NC4H8S ( 7 ), and ‐NC4H8O ( 8 )), was accomplished by the sequential living cationic polycondensation of N‐silylphosphoranimines, using the mono‐end‐capped initiator [Ph3P?N?PCl3][Cl] ( 3 ). The self‐assembly of the phosphazene BCPs 6 – 8 led to chiral porous films. The functionality present on those polymers affected their self‐assembly behaviour resulting in the formation of pores of different diameters (Dn=111 ( 6 ), 53 ( 7 ) and 77 nm ( 8 )). The specific functionalisation of the pores was proven by decorating the films with gold nanoparticles (AuNPs). Thus, the BCPs 6 and 7 , having pyridine and thiomorpholine groups, respectively, were treated with HAuCl4, followed by reduction with NaBH4, yielding a new type of block copolyphosphazenes, which self‐assembled into chiral porous films specifically decorated with AuNPs at the edge of the pores. 相似文献
13.
Yu Na Lim Soo Kyung Chae Woongbin Yim Ji‐Yong Park Woojin Yoon Hoseop Yun Eunha Kim Seung Uk Son Hye‐Young Jang 《应用有机金属化学》2019,33(3)
The reaction of [(domppp) Pd (OAc)2] [domppp = 1,3‐bis (di‐o‐methoxyphenylphosphino)propane] and imidazolium‐functionalized carboxylic acids containing various anions (Br?, PF6?, SbF6? and BF4?) resulted in the formation of nano‐sized Pd (II) aggregates under template‐free conditions. The rate of formation of aggregates can be modulated by changing the anion, affecting the rate of polymerization of CO and olefins without fouling. Herein, we describe the analysis of Pd (II) catalysts by dynamic light scattering, atomic force microscopy, X‐ray photoelectron spectroscopy and X‐ray crystallography, and co‐ and terpolymerization results including the catalytic activity, and bulk density and molecular weight of polymers. 相似文献
14.
Jiří Schulz Anna K. Renfrew Ivana Císařová Paul J. Dyson Petr Štěpnička 《应用有机金属化学》2010,24(5):392-397
The polar phosphanyl‐carboxamide, 1′‐(diphenylphosphanyl)‐1‐[N‐(2‐hydroxyethyl)carbamoyl]ferrocene ( 1 ), reacts readily with hydrogen peroxide and elemental sulfur to give the corresponding phosphane‐oxide and phosphane‐sulfide, respectively, and with platinum(II) and palladium(II) precursors to afford various bis(phosphane) complexes [MCl2( 1 ‐κP)2] (M = trans‐Pd, trans‐Pt and cis‐Pt). The anticancer activity of the compounds was evaluated in vitro with the complexes showing moderate cytotoxicities towards human ovarian cancer cells. Moreover, the biological activity was found to be strongly influenced by the stereochemistry, with trans‐[PtCl2( 1 ‐κP)2] being an order of magnitude more active than the corresponding cis isomer. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
15.
Novel Transition‐Metal (M=Cr,Mo, W,Fe) Carbonyl Complexes with Bis(guanidinato)silicon(II) Ligands
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Felix M. Mück Dorit Kloß Johannes A. Baus Dr. Christian Burschka Prof. Dr. Reinhold Tacke 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(31):9620-9626
The donor‐stabilized silylene 2 (the first bis(guanidinato)silicon(II ) complex) reacts with the transition‐metal carbonyl complexes [M(CO)6] (M=Cr, Mo, W) to form the respective silylene complexes 7 – 10 . In the reactions with [M(CO)6] (M=Cr, Mo, W), the bis(guanidinato)silicon(II ) complex 2 behaves totally different compared with the analogous bis(amidinato)silicon(II ) complex 1 , which reacts with [M(CO)6] as a nucleophile to replace only one of the six carbonyl groups. In contrast, the reaction of 2 leads to the novel spirocyclic compounds 7 – 9 that contain a four‐membered SiN2C ring and a five‐membered MSiN2C ring with a M?Si and M?N bond (nucleophilic substitution of two carbonyl groups). Compounds 7 – 10 were characterized by elemental analyses (C, H, N), crystal structure analyses, and NMR spectroscopic studies in the solid state and in solution. 相似文献
16.
Filippou AC Chernov O Schnakenburg G 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(48):13574-13583
An efficient method for the synthesis of the first N‐heterocyclic carbene (NHC)‐stabilized halosilylidyne complexes is reported that starts from SiBr4. In the first step, SiBr4 was treated with one equivalent of the N‐heterocyclic carbene 1,3‐bis[2,6‐bis(isopropyl)phenyl]imidazolidin‐2‐ylidene (SIdipp) to give the 4,5‐dihydroimidazolium salt [SiBr3(SIdipp)]Br ( 1‐Br ), which then was reduced with potassium graphite to afford the silicon(II) dibromide–NHC adduct SiBr2(SIdipp) ( 2‐Br ) in good yields. Heating 2‐Br with Li[CpCr(CO)3] afforded the complex [Cp(CO)2Cr?SiBr(SIdipp)] ( 3‐Br ) upon elimination of CO. Complex 3‐Br features a trigonal‐planar‐coordinated silicon center and a very short Cr?Si double bond. Similarly, the reaction of SiCl2(SIdipp) ( 2‐Cl ) with Li[CpCr(CO)3] gave the analogous chloro derivative [Cp(CO)2Cr?SiCl(SIdipp)] ( 3‐Cl ). Complex 3‐Br undergoes an NHC exchange with 1,3‐dihydro‐4,5‐dimethyl‐1,3‐bis(isopropyl)‐2H‐imidazol‐2‐ylidene (IMe2iPr2) to give the complex [Cp(CO)2CrSiBr(IMe2iPr2)2] ( 4‐Br ). Compound 4‐Br features a distorted‐tetrahedral four‐coordinate silicon center. Bromide abstraction occurs readily from 4‐Br with Li[B(C6F5)4] to give the putative silylidene complex salt [Cp(CO)2Cr?Si(IMe2iPr2)2][B(C6F5)4], which irreversibly dimerizes by means of an Si‐promoted electrophilic activation of one carbonyl oxygen atom to yield the dinuclear siloxycarbyne complex [Cp(CO)Cr{(μ‐CO)Si(IMe2iPr2)2}2‐ Cr(CO)Cp][B(C6F5)4]2 ( 5 ). All compounds were fully characterized, and the molecular structures of 2‐Br – 5‐Br were determined by single‐crystal X‐ray diffraction. DFT calculations of 3‐Br and 3‐Cl and their carbene dissociation products [Cp(CO)2Cr?Si? X] (X=Cl, Br) were carried out, and the electronic structures of 3‐Br , 3‐Cl and [Cp(CO)2Cr?Si? X] were analyzed by the natural bond orbital method in combination with natural resonance theory. 相似文献
17.
Coordination of Alkaline Earth Metal Ions in the Inverted Cucurbit[7]uril Supramolecular Assemblies Formed in the Presence of [ZnCl4]2− and [CdCl4]2−
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Qing Li Yun‐Qian Zhang Qian‐Jiang Zhu Sai‐Feng Xue Zhu Tao Prof. Dr. Xin Xiao 《化学:亚洲杂志》2015,10(5):1159-1164
A convenient method to isolate inverted cucurbit[7]uril (iQ[7]) from a mixture of water‐soluble Q[n]s was established by eluting the soluble mixture of Q[n]s on a Dowex (H+ form) column so that iQ[7] could be selected as a ligand for coordination and supramolecular assembly with alkaline earth cations (AE2+) in aqueous HCl solutions in the presence of [ZnCl4]2? and [CdCl4]2? anions as structure‐directing agents. Single‐crystal X‐ray diffraction analysis revealed that both iQ[7]–AE2+–[ZnCl4]2?–HCl and iQ[7]–AE2+–[CdCl4]2?–HCl interaction systems yielded supramolecular assemblies, in which the [ZnCl4]2? and [CdCl4]2? anions presented a honeycomb effect, and this resulted in the formation of linear iQ[7]/AE2+ coordination polymers through outer‐surface interactions of Q[n]s. 相似文献
18.
Yasushi Nishihara Yukiko Doi Seisuke Izawa Horng‐Yi Li Yoshiaki Inoue Masaaki Kojima Jwu‐Ting Chen Kentaro Takagi 《Journal of polymer science. Part A, Polymer chemistry》2010,48(2):485-491
Doubly fuctionalized polar norbornenes bearing the cyano and ester groups in 2,3‐positions are synthesized and enantiomers are separated by high performance liquid chromatography (HPLC) with a chiral stationary phase. These optically active monomers are polymerized by ruthenium carbene catalysts, and high yields of the polymers were obtained. The chiral monomer bearing ethyl ester gave an optically active polymer of lower, but opposite sign of optical rotation (monomer [α]D = +61.0°, polymer [α]D = ?3.1°). The circular dichroism (CD) of the obtained chiral polymers gave a Cotton effect. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 485–491, 2010 相似文献
19.
Interaction between Anions and Cationic Metal Complexes Containing Tridentate Ligands with exo‐CH Groups: Complex Stability and Hydrogen Bonding
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Dr. Héctor Martínez‐García Dr. Dolores Morales Dr. Julio Pérez Dr. Marcos Puerto Dr. Ignacio del Río 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(19):5821-5834
[Re(CO)3([9]aneS3)][BAr′4] ( 1 ), prepared by reaction of ReBr(CO)5, 1,4,7‐trithiacyclononane ([9]aneS3) and NaBAr′4, forms stable, soluble supramolecular adducts with chloride ( 2 ), bromide, methanosulfonate ( 3 ) and fluoride ( 4 ) anions. These new species were characterized by IR, NMR spectroscopy and, for 2 and 3 , also by X‐ray diffraction. The results of the solid state structure determinations indicate the formation of CH???X hydrogen bonds between the anion (X) and the exo‐C?H groups of the [9]aneS3 ligand, in accord with the relatively large shifts found by 1H NMR spectroscopy in dichloromethane solution for those hydrogens. The stability of the chloride adduct contrasts with the lability of the [9]aneS3 ligand in allyldicarbonyl molybdenum complexes recently studied by us. With fluoride, in dichloromethane solution, a second, minor neutral dimeric species 5 is formed in addition to 4 . In 4 , the deprotonation of a C?H group of the [9]aneS3 ligand, accompanied by C?S bond cleavage and dimerization, afforded 5 , featuring bridging thiolates. Compounds [Mo(η3‐methallyl)(CO)2(TpyN)][BAr′4] ( 6 ) and [Mo(η3‐methallyl)(CO)2(TpyCH)][BAr′4] ( 7 ) were synthesized by the reactions of [MoCl(η3‐methallyl)(CO)2(NCMe)2], NaBAr′4 and tris(2‐pyridyl)amine (TpyN) or tris(2‐pyridyl)methane (TpyCH) respectively, and characterized by IR and 1H and 13C NMR spectroscopy in solution, and by X‐ray diffraction in the solid state. Compound 6 undergoes facile substitution of one of the 2‐pyridyl groups by chloride, bromide, and methanosulfonate anions. Stable supramolecular adducts were formed between 7 and chloride, bromide, iodide, nitrate, and perrhenate anions. The solid state structures of these adducts ( 12 – 16 ) were determined by X‐ray diffraction. Binding constants in dichloromethane were calculated from 1H NMR titration data for all the new supramolecular adducts. The signal of the bridgehead C?H group is the one that undergoes a more pronounced downfield shift when tetrabutylammonium chloride was added to 7 , whereas smaller shifts were found for the 2‐pyridyl C(3)?H groups. In agreement, both types of C?H groups form hydrogen bonds to the anions in the solid state structures. 相似文献
20.
Self‐immobilized nickel and iron diimine catalysts bearing one or two allyl groups of [ArN?C]2(C10H6)NiBr2 [Ar = 4‐allyl‐2,6‐(i‐Pr)2C6H2] ( 1 ), [ArN?C(Me)][Ar′N? C(Me)]C5H3NFeCl2 [Ar = Ar′ = 4‐allyl‐2,6‐(i‐Pr)2C6H3, Ar = 2,6‐(i‐Pr)2C6H3, and Ar′ = 4‐allyl‐2,6‐(i‐Pr)2C6H3] were synthesized and characterized. All three catalysts were investigated for olefin polymerization. As a result, these catalysts not only showed high activities as the catalyst free from the allyl group, such as [ArN?C]2C10H6NiBr2 (Ar = 2,6‐(i‐Pr)2C6H2)], but also greatly improved the morphology of polymer particles to afford micron‐granula polyolefin. The self‐immobilization of catalysts, the formation mechanism of microspherical polymer, and the influence on the size of the particles are discussed. The molecular structure of self‐immobilized nickel catalyst 1 was also characterized by crystallographic analysis. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1018–1024, 2004 相似文献