Carbazole substituted N-acylated linear polyethylenimines (PEI). synthesis and characterization of poly[N-(9-carbazolyl)acetylethylenimine] and poly[N-(2-(9-carbazolyl))propanoylethylenimine]

The synthesis of carbazola substituted N-acylated polyethylenimines, namely, poly[N-(9-carbazolyl)acetylethylenimine] 20 and poly[N-(2-(9-carbazolyl))propanoylethylenimine] 21 by a grafting reaction onto PEI and isomerization polymerization of the carbazole substituted 2-oxazolines is reported. A complete acylation of amino groups in PEI by the 9-carbazolylacetyl groups was achieved by the p-nitrophenyl active ester method but PEI was only partially N-acylated by the 2-(9-carbazolyl)propanoyl groups under similar reaction conditions. The carbazole substituted 2-oxazolines, namely, 2-(9-carbazolyl)methyl-2-oxazoline 18 and (R,S)-2-[1-(9-carbazolyl)]ethyl-2-oxazoline 19 , were prepared by a base induced cyclization of ß-chloroamides. The ring-opening isomerization polymerization of 18 and 19 in the molten state with a cationic initiator (dimethyl sulfate, methyl triflate, or ethylene glycol ditosylate) gave 20 and 21. Gel permeation chromatography of 20 and 21 obtained with different monomerto-initiator ratios gave evidence of a chain transfer reaction with the monomer. The polymers were characterized by elemental analyses, IR, and ¹H-NMR spectroscopy.     

Indoprofen类似物的合成和表征

以邻硝基苯甲醛为超始原料，合成2-溴甲基-3-喹啉酸乙酯中间体，其分别与 苯胺、2-氯代苯胺、3-氯代苯胺、2-甲基苯胺和3-甲基苯胺发生Williamson反应， Williamson反应产物经闭环反应，得到新化合物2，3-二氢-1-氧代-2-苯基-1H-吡 咯并[3，4-b]喹啉（4a），2，3-二氢-1-氧代-2-（2-氯代苯基）-1H-吡咯并[3， 4-b]喹啉（4b），2，3-二氢-1-氧代-2-（3-氯代苯基）-1H-吡咯并[3,4-b]喹啉（ 4c），2，3-二氢-1-氧代-2-（2-甲基苯基）-1H-吡咯并[3，4-b]喹啉（4d）和2， 3-二氢-1-氧代-2-（3-甲基苯基）-1H-吡咯并[3，4-b]喹啉（4e）。12个新化合物 由元素分析、红外光谱、核磁共振氢谱、质谱予以证实。     

1,3-Oxathiole and Thiirane Derivatives from the Reactions of Azibenzil and α-diazo amides with thiocarbonyl compounds

The reactions of α-diazo ketones 1a,b with 9H-fluorene-9-thione ( 2f ) in THF at room temperature yielded the symmetrical 1,3-dithiolanes 7a,b , whereas 1b and 2,2,4,4-tetramethylcyclobutane-1,3-dithione ( 2d ) in THF at 60° led to a mixture of two stereoisomeric 1,3-oxathiole derivatives cis- and trans- 9a (Scheme 2). With 2-diazo-1,2-diphenylethanone ( 1c ), thio ketones 2a–d as well as 1,3-thiazole-5(4H)-thione 2g reacted to give 1,3-oxathiole derivatives exclusively (Schemes 3 and 4). As the reactions with 1c were more sluggish than those with 1a,b , they were catalyzed either by the addition of LiClO₄ or by Rh₂(OAc)₄. In the case of 2d in THF/LiClO₄ at room temperature, a mixture of the monoadduct 4d and the stereoisomeric bis-adducts cis- and trans- 9b was formed. Monoadduct 4d could be transformed to cis- and trans- 9b by treatment with 1c in the presence of Rh₂(OAc)₄ (Scheme 4). Xanthione ( 2e ) and 1c in THF at room temperature reacted only when catalyzed with Rh₂(OAc)₄, and, in contrast to the previous reactions, the benzoyl-substituted thiirane derivative 5a was the sole product (Scheme 4). Both types of reaction were observed with α-diazo amides 1d,e (Schemes 5–7). It is worth mentioning that formation of 1,3-oxathiole or thiirane is not only dependent on the type of the carbonyl compound 2 but also on the α-diazo amide. In the case of 1d and thioxocyclobutanone 2c in THF at room temperature, the primary cycloadduct 12 was the main product. Heating the mixture to 60°, 1,3-oxathiole 10d as well as the spirocyclic thiirane-carboxamide 11b were formed. Thiirane-carboxamides 11d–g were desulfurized with (Me₂N)₃P in THF at 60°, yielding the corresponding acrylamide derivatives (Scheme 7). All reactions are rationalized by a mechanism via initial formation of acyl-substituted thiocarbonyl ylides which undergo either a 1,5-dipolar electrocyclization to give 1,3-oxathiole derivatives or a 1,3-dipolar electrocyclization to yield thiiranes. Only in the case of the most reactive 9H-fluorene-9-thione ( 2f ) is the thiocarbonyl ylide trapped by a second molecule of 2f to give 1,3-dithiolane derivatives by a 1,3-dipolar cycloaddition.     

Synthesis and polymerization of 2,5-dimethylene-2,5-dihydrothieno[3,2-b]thiophene derivatives: The structure and reactivity of quinonoid monomers

Novel 2,5-dimethylene-2,5-dihydrothieno[3,2-b]thiophene derivatives such as 2,5-bis[di(ethylthio)methylene]-2,5-dihydrothieno[3,2-b]thiophene ( 4b ) and 2,5-bis[cyano(ethylthio)methylene]-2,5-dihydrothieno[3,2-b]thiophene ( 4c ) were successfully synthesized as isolable crystals. Polymerization behavior of 2,5-bis(dicyanomethylene)-2,5-dihydrothieno[3,2-b]thiophene ( 4a ), 4b , and 4c was investigated. 4a , 4b , and 4c are not homopolymerizable with any initiators and also not copolymerizable with vinyl monomers such as styrene (St), methyl methacrylate, and acryronitrile except for an alternating copolymerization of 4a with St. 4a , 4b , and 4c did not copolymerize with 7,8-bis(butoxycarbonyl)-7,8-dicyanoquinodimethane (BCQ) as a highly conjugated comonomer and instead only homopolymer of BCQ was obtained, indicating that they are much less reactive than BCQ. To obtain the relative reactivity among 1c , 2c , and 4c , the rate of addition reaction of 2,2′-azobis(isobutyronitrile) (AIBN) with 4c was compared with those of AIBN with 7,8-bis(ethylthio)-7,8-dicyanoquinodimethane ( 1c ) and with 2,5-bis[cyano(ethylthio)methylene]-2,5-dihydrothiophene ( 2c ) by NMR spectroscopy and analyzed with the first-order kinetics. The relative reactivity among 1c , 2c , and 4c was found to be as follows: 1c > 4c > 2c . The relationship between structure and reactivity for the quinonoid compounds was discussed. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3027–3039, 1999     

Palladium Aryl Sulfonate Phosphine Catalysts for the Copolymerization of Acrylates with Ethene

The reaction of 2‐[bis(2‐methoxy‐phenyl)phosphanyl]‐4‐methyl‐benzenesulfonic acid (a) and 2‐[bis(2′,6′‐dimethoxybiphenyl‐2‐yl)phosphanyl]benzenesulfonic acid (b) with dimethyl(N,N,N′,N′‐tetramethylethylenediamine)‐palladium(II) (PdMe₂(TMEDA)) leads to the formation of TMEDA bridged palladium based polymerization catalysts ( 1a and 1b ). Upon reaction with pyridine, two mononuclear catalysts are formed ( 2a and 2b ). These catalysts are able to homopolymerize ethylene and also copolymerize ethylene with acrylates or with norbornenes. With ligand b , high molecular weight polymers are formed in high yields, but higher comonomer incorporations are obtained with ligand a .

     

Monomers for Adhesive Polymers, 6

Summary: 1,3‐Bis(methacrylamido)propane‐2‐yl dihydrogen phosphate ( 1 ) was synthesised by phosphorylation of 1,3‐bis(methacrylamido)‐2‐hydroxypropane ( 2 ) with phosphorus oxychloride in tetrahydrofuran (THF) in the presence of triethylamine (TEA). The structure of the new monomer 1 was characterised by IR, ¹H NMR, ¹³C NMR and ³¹P NMR spectroscopies, elemental analysis and mass spectrometry. The monomer dissolves well in water, ethanol or aqueous THF and shows an improved hydrolytic stability compared to the corresponding methacrylate‐based dihydrogen phosphates. 1 was homopolymerised in ethanol with 2,2′‐azoisobutyronitrile (AIBN) as the initiator at 55–75 °C under the formation of an insoluble, cross‐linked product. Aqueous solutions of 1 are strongly acidic and enable to etch enamel and dentin. Nevertheless, 1 did not show any cytotoxic effect. Furthermore, the adhesive properties of 1 were measured.

1,3‐Bis(methacrylamido)propane‐2‐yl dihydrogen phosphate.     

Poly[trans-1-(3-vinyl-9-carbazolyl)-2-(9-carbazolyl)cyclobutane]. Synthesis and comparison with poly(9-ethyl-3-vinylcarbazole)

Trans-1-(3-vinyl-9-carbazolyl)-2-(9-carbazolyl)cyclobutane(I) was synthesized. Homopolymerization of I and copolymerization with 9-ethyl-3-vinylcarbazole(II) were conducted cationically. It was found that I polymerized to high molecular weight polymers (< 10⁵) with good yields, although its polymerizability was lower than that of II. Copolymer composition was determined by gel permeation chromatology (GPC) analysis, based on the remaining monomer ratio. Fluorescence spectroscopy indicated that poly(I) did not form excimer. Excimer emission gradually appeared with increasing II content in poly(I-co-II) to the homopolymer of II. This difference between poly(I) and poly(II) was attributed to the crowded and sterically distorted chromophore assemblies in poly(I). ¹H- and ¹³C-NMR spectroscopy of cyclobutane groups in poly(I) compared with that in the monomer model compound supported the conclusion derived from fluorescence study.     

基于咔唑的新型碳酰腙衍生物的合成及蛋白酪氨酸磷酸酶1B(PTP1B)抑制活性评价

合成出了一系列新型基于咔唑的单-/双-碳酰腙衍生物3和4.利用1H NMR、13C NMR、IR和元素分析对其进行了结构表征.评价了目标化合物对蛋白酪氨酸磷酸酶1B(PTP1B)的抑制活性,讨论了结构与活性的关系.实验结果显示,大部分化合物对PTP1B具有良好的抑制活性,其中1,5-双[(9-丁基-3-咔唑基)亚甲基]碳酰腙(4c)的抑制活性最高,IC50=(4.81±0.41)mmol/L,且活性高于对照药物齐墩果酸.对目标化合物1-[(9-庚基-3-咔唑基)亚甲基]碳酰腙(3f)和4c进行分子对接研究和密度泛函理论(DFT)计算.分子对接结果表明,化合物3f和4c结合到PTP1B酶由螺旋α3和α6形成的活性位点,与PTP1B酶通过氢键、极性、疏水和p-p等相互作用形成了稳定的复合物.     

Reactions of Diferrocenylmorpholino- and -Methylsulfanyl-cyclopropenylium Salts with β-Dicarbonyl Compounds and Diethyl Malonate

2,3-Diferrocenyl-1-morpholinocyclopropenylium tetrafluoroborate reacts with ethyl acetoacetate, ethyl benzoylacetate, and diethyl malonate in the presence of triethylamine to yield 3-[acyl(ethoxycarbonyl)]-, 3-(diethoxycarbonyl)-methyl-3-morpholino-1,2-diferrocenylcyclopropenes (3a–c), and 3-[acyl(ethoxycarbonyl)]- and (diethoxycarbonyl)-methylidene-1,2-diferrocenylcyclopropenes (4a–c) in a ca. 1:1.5 ratio. 2,3-Diferrocenyl-1-methylsulfanylcyclopropenylium iodide with the same substrates affords compounds 4a,b (～10–15%), 3-[acyl(ethoxycarbonyl)]methyl-3-methylsulfanyl-1,2-diferrocenylcyclopropenes (5a,b) (～8–10%), 2-acyl-3,4-diferrocenyl-5-methylsulfanylcyclopentadienones (6a,b), ethyl 2-acyl-3,4-diferrocenyl-5-methylsulfanylpenta-2,4-dienoates (7a,b; 8a,b), and ethyl 3,4-diferrocenyl-2-methylsulfanyl-6-oxohexa(hepta)-2,4-dienoates (9a,b). The spatial structure of ethyl Z,E-3,4-diferrocenyl-2-methylsulfanyl-6-oxohepta-2,4-dienoate (9b) was established based on the data from x-ray diffraction analysis. Electrochemical properties of 3-[acyl(ethoxycarbonyl)]- and (diethoxycarbonyl)-methylidene-1,2-diferrocenylcyclopropenes (4a–c) are studied.     

Heteroleptic Lanthanide Complexes with Aryloxide Ligands. Synthesis and Structural Characterization of Divalent and Trivalent Samarium Aryloxide/Halide and Aryloxide/Cyclopentadienide Complexes

Synthesis of a new class of heteroleptic samarium aryloxide complexes has been achieved by the use of homoleptic samarium(II) bis(aryloxide) Sm(OAr)(2)(THF)(3) (1, Ar = C(6)H(2)Bu(t)(2)-2,6-Me-4) as a starting material, which is easily obtained by reaction of Sm(N(SiMe(3))(2))(2)(THF)(2) with 2 equiv of ArOH in THF. 1 reacts with 1 equiv of SmI(2) in THF to give Sm(II) mixed aryloxide/iodide [(ArO)Sm(&mgr;-I)(THF)(3)](2) (2), which adopts a dimeric structure via very weak Sm.I (3.534(2) ?) interactions. Reaction of 2 with C(5)Me(5)K in THF/HMPA affords the corresponding Sm(II) aryloxide/cyclopentadienide (C(5)Me(5))Sm(OAr)(HMPA)(2) (3). Oxidation of 1 with 0.5 equiv of I(2) in THF gives monomeric samarium(III) aryloxide/iodide (ArO)(2)SmI(THF)(2) (4), while the similar reaction of 1 with ClCH(2)CH(2)Cl or (t)BuCl in THF affords dimeric samarium(III) aryloxide/chloride [(ArO)(2)Sm(&mgr;-Cl)(THF)](2) (5). Crystal data for 1: monoclinic, space group P2(1), a = 9.903(3) ?, b = 16.718(5) ?, c = 13.267(2) ?, beta = 95.17(2) degrees, V = 2187(2) ?(3), Z = 2, D(c) = 1.223 g cm(-)(3), R = 0.0634. Crystal data for 2.2THF: monoclinic, space group P2(1)/a, a = 18.330(6) ?, b = 14.320(4) ?, c = 13.949(3) ?, beta = 103.16(2) degrees, V = 3563(2) ?(3), Z = 2, D(c) = 1.46 g cm(-)(3), R = 0.0606. Crystal data for 3: triclinic, space group P&onemacr;, a = 10.528(1) ?, b = 12.335(2) ?, c = 19.260(2) ?, alpha = 101.33(1) degrees, beta = 95.230(9) degrees, gamma = 108.54(1) degrees, V = 2293.1(5) ?(3), Z = 2, D(c) = 1.25 g cm(-)(3), R = 0.0358. Crystal data for 4: monoclinic, space group C2/c, a = 17.191(7) ?, b = 10.737(6) ?, c = 21.773(7) ?, beta = 98.80(3) degrees, V = 3971(3) ?(3), Z = 4, D(c) = 1.44 g cm(-)(3), R = 0.0467. Crystal data for 5: monoclinic, space group P2(1)/n, a = 13.750(3) ?, b = 17.231(3) ?, c = 14.973(6) ?, beta = 95.81(2) degrees, V = 3529(2) ?(3), Z = 2, D(c) = 1.31 g cm(-)(3), R = 0.0557.     

Supramolecular Micellization of Diblock Copolymer Mixtures Mediated by Hydrogen Bonding for the Observation of Separated Coil and Chain Aggregation in Common Solvents

This paper describes a new approach towards preparing self‐assembled hydrogen‐bonded complexes that have vesicle and patched spherical structures from two species of block copolymer in non‐selective solvents. The assembly of vesicles from the intermolecular complex formed after mixing polystyrene‐block‐poly(4‐vinyl phenol) (PS‐b‐PVPh) with poly(methyl methacrylate)‐block‐poly(4‐vinylpyridine) (PMMA‐b‐P4VP) in tetrahydrofuran (THF) is driven by strong hydrogen bonding between the complementary binding sites on the PVPh and P4VP blocks. In contrast, well‐defined patched spherical micelles form after blending PS‐b‐PVPh with PMMA‐b‐P4VP in N,N‐dimethylformamide (DMF): weaker hydrogen bonds form between the PVPh and P4VP blocks in DMF, relative to those in THF, which results in the formation of spherical micelles that have compartmentalized coronas that consist of PS and PMMA blocks.

     

Potassium hydroxide-mediated novel rearrangement of 2-alkyl-sulfonyl-2-arylsulfonyl-1-phenylethanones to 1-aryl-2-(arylsulfonylmethanesulfonyl)ethanones

Treatment of a solution of a mixture of 1-aryl-2-arylsulfonylethanones 9 and alkylsulfonyl chlorides (1.5-2.0 equiv) in THF at 0 degree C with potassium hydroxide (8 equiv) for 10 min gave a rearrangement product, i.e., 1-aryl-2-(arylsulfonylmethanesulfonyl)ethanones 8, in excellent yields. Regiospecific methyl- and ethylation at the methylene carbon sandwiched between two sulfonyl groups of 8 could be achieved by the reactions of 7i-j with LDA (1 equiv) in THF at room temperature, respectively.     

(C_5H_9C_5H_4)_3NdBrLi(THF)_3和(C_5H_9C_5H_4)_3SmTHF的合成与结构

无水三氯化钕与环戊烷基环戊二烯钠、溴化锂(1:2:1摩尔比)反应,除去不溶物和溶剂后,产物在己烷/四氢呋喃溶剂中冷冻得到兰紫色晶体(C5H9C5H4)3NdBrLi(THF)3(配合物1)。其中心金属Nd3+的配位数为10,以η5与3个环戊二烯基相连,并通过单溴原子桥连锂原子,形成双核结构。该晶体属三斜晶系,P`1空间群。晶体学参数为a=12.048(2)、b=13.498(3)、c=13.831(3);α=104.16(3)、β=104.07(3)、γ=95.96(3); V=2083.3(7)3、Z=2、Dc=1.35Mg/m3、Mr=847.01gmol-1、F(000)=874。无水三氯化钐与环戊烷基环戊二烯钠(1:3)反应,产物在-30oC下的己烷溶剂中结晶得桔红色晶体(C5H9C5H4)3SmTHF(配合物2)。该晶体属正交晶系,Fdd2空间群。晶胞参数a=28.175(5) 、b=46.24(2)、c=9.167(4);V=11943(8)3、Z=16、Dc=1.38Mg/m3、 Mr=622.11 g·mol-1、F(000)=5136。10配位的金属Sm3+与3个环戊二烯基以η5相连,并结合一个四氢呋喃溶剂分子。     

Synthesis and structural characterization of Sm(II) and Yb(II) complexes containing sterically demanding, chelating secondary phosphide ligands

Metathesis between [(Me3Si)2CH)(C6H4-2-OMe)P]K and SmI2(THF)2 in THF yields [([Me3Si]2CH)(C6H4-2-OMe)P)2Sm(DME)(THF)] (1), after recrystallization. A similar reaction between [(Me3Si)2CH)(C6H3-2-OMe-3-Me)P]K and SmI2(THF)2 yields [([Me3Si]2CH)(C6H3-2-OMe-3-Me)P)2Sm(DME)].Et2O (2), while reaction between [(Me3Si)2CH)(C6H4-2-CH2NMe2)P]K and either SmI2(THF)2 or YbI2 yields the five-coordinate complex [([Me3Si]2CH)(C6H4-2-CH2NMe2)P)2Sm(THF)] (3) or the solvent-free complex [([Me3Si]2CH)(C6H4-2-CH2NMe2)P)2Yb] (4), respectively. X-ray crystallography shows that complex 2 adopts a distorted cis octahedral geometry, while complex 1 adopts a distorted pentagonal bipyramidal geometry (1, triclinic, P1, a = 11.0625(9) A, b = 15.924(6) A, c = 17.2104(14) A, alpha = 72.327(2) degrees, beta = 83.934(2) degrees, gamma = 79.556(2) degrees, Z = 2; 2, monoclinic, P2(1), a = 13.176(4) A, b = 13.080(4) A, c = 14.546(4) A, beta = 95.363(6) degrees, Z = 2). Complex 3 crystallizes as monomers with a square pyramidal geometry at Sm and exhibits short contacts between Sm and the ipso-carbon atoms of the ligands (3, monoclinic, C2/c, a = 14.9880(17) A, b = 13.0528(15) A, c = 24.330(3) A, beta = 104.507(2) degrees, Z = 4). Whereas preliminary X-ray crystallographic data for 4 indicate a monomeric structure in the solid state, variable-temperature 1H, 13C(1H), 31P(1H), and 171Yb NMR spectroscopies suggest that 4 undergoes an unusual dynamic process in solution, which is ascribed to a monomer-dimer equilibrium in which exchange of the bridging and terminal phosphide groups may be frozen out at low temperature.     

第五、六族元素的有机化合物在有机合成中应用的研究 XVII.胂叶立德与氟代烯烃的反应

Reaction of perfluoropropylene (2a) with cyanomethylene- triphenylarsorane (1b) gave cyano-2, 3, 3, 3-tetrafluoropropionylmethylene-triphenylarsorane (4b), and with benzoylmethylene-(1c) and acetylmethylene-triphenylarsorane (1d) gave benzoyl-(3c) and acetyl-(trans-perfluoropropen-1-yl)- methylene-triphenylarsorane (3d), respectively 3c and 3d could be converted to benzoyl-(4c) and acetyl-2, 3, 3, 3-tetrafluoropropionyl -methylene triphenylarsorane (4d), respectively by refluxing with moist benzene. Reaction of carbomethoxymethylene- triphenylphosphorane (1e) with perfluoropropylene was similar to that of arsorane. However, benzoylmethylene-and acetylmethylene- triphenylphosphorane were unreactive towards perfluoropropylene. Reaction of carbomethoxymethylene-triphenylarsoraen (1a) with trifluorochloroethylene gave carbomethoxyfluoroacetylmenthylene- triphenylarsorane (4f) in low yield. when the residue was treated with methanol, difluorotriphenylarsorano and methyl- fluorochloroacetate (8) were obatined. The structures of the aforementioned products are ascertained by elemental analyses, IR, ^1H NMR, ^1^9F NMR and mass spectra.     

DMAO-activated Rare-earth Metal Catalysts for Styrene and Its Derivative Polymerization

The catalytic performance of rare-earth metal dialkyl complexes in combination with DMAO(dry methylaluminoxane) is explored.In the presence of 60 equivalents of DMAO,the half-sandwich complex(C₁₃H₈ CH₂ Ph)Sc(CH₂ SiMe₃)₂(THF)(1) is inert for styrene polymerization,but(C₅ Me₄ Ph)Sc(CH₂ C₆ H₄ NMe₂-o)₂(2) converts 18% styrene into syndiotactic polystyrene.Und...     

Palladium-catalyzed cross-alkynylation of aryl bromides by sodium tetraalkynylaluminates

Sodium tetraalkynylaluminates (1-4), prepared from NaAlH4 and terminal alkynes, cross-couple with aryl bromides in the presence of Pd(0) and Pd(II) catalysts. The reactions take place in boiling THF or DME. The process is applicable to both homo- and heterocyclic aryl bromides and can be used for conversion of polybromo compounds into polyalkynes. The reactions are high yielding and selective, free of undesired homocoupling and hydrogenolysis processes. The reagents selectively react with the ring-bound bromine atoms but do not affect chloro, cyano, triflate, or ester functions.     

Terphenyl ligand systems in lanthanide chemistry: use of the 2,6-di(1-naphthyl)phenyl ligand for the synthesis of kinetically stabilized complexes of trivalent ytterbium, thulium, and yttrium

The molecular structures of terphenyl derivatives of trivalent ytterbium, thulium, and yttrium of general composition DnpLnCl(2)(THF)(2) [Dnp = 2,6-di(1-naphthyl)phenyl] are reported. The complexes (Ln = Yb: 1; Ln = Tm: 2; Ln = Y: 3) are synthesized by reaction of 1 equiv of DnpLi with 1 equiv of LnCl(3) (Ln = Yb, Tm, or Y) in tetrahydrofuran at room temperature in 50% yield. Attempts to prepare a Dnp scandium compound gave heterobimetallic [(THF)(3)Sc(2)OCl(5)Li(THF)](2) (4) in low yield. 1 crystallizes in the monoclinic space group C2/c. Crystal data for 1 at 203 K: a = 14.333(3) A, b = 16.353(3) A, c = 12.427(2) A, beta = 91.021(4) degrees, Z = 4, D(calcd) = 1.637 g cm(-3), R(1) = 4.44%. 2 crystallizes in the monoclinic space group C2/c. Crystal data for 2 at 203 K: a = 14.333(1) A, b = 16.374(2) A, c = 12.404(1) A, beta = 90.934(2) degrees, Z = 4, D(calcd) = 1.628 g cm(-3), R(1) = 3.00%. 3 crystallizes in the monoclinic space group C2/c. Crystal data for 3 at 203 K: a = 14.348(3) A, b = 16.476(3) A, c = 12.356(2) A, beta = 90.987(4) degrees, Z = 4, D(calcd) = 1.441 g cm(-3), R(1) = 5.62%. 4 crystallizes in the monoclinic space group P2(1)/n. Crystal data for 4 at 203 K: a = 11.0975(9) A, b = 11.0976(9) A, c = 21.3305(18) A, beta = 94.718(2) degrees, Z = 2, D(calcd) = 1.051 g cm(-3), R(1) = 3.45%. Complexes 1-3 represent examples of novel chiral (racemic) organometallic complexes of the lanthanide elements ytterbium and thulium and the group 3 element yttrium, respectively. The molecular structures of monomeric 1-3 exhibit distorted trigonal-bipyramidal coordination environments at the metal center, with the two oxygen atoms of the tetrahydrofuran ligands occupying the axial positions of a trigonal-bipyramidal coordination polyeder. The molecular structure of the scandium compound 4 shows a complex polynuclear heterobimetallic arrangement.     

Lanthanide-transition-metal carbonyl complexes. 1. Syntheses and structures of ytterbium(II) solvent-separated ion pairs and isocarbonyl polymeric arrays of tetracarbonylcobaltate

Transmetalation reactions of metallic ytterbium with Hg[Co(CO)(4)](2) in the coordinating solvents pyridine and THF yield the solvent-separated ion pairs [Yb(L)(6)] [Co(CO)(4)](2) (1a, L = Pyr; 2a, L = THF). The IR spectrum of 1a in pyridine indicates that the tetracarbonylcobaltate anion is not directly bonded to the divalent Yb cation owing to the strong coordinating ability of pyridine. On the other hand, IR spectra of 2a in THF are concentration dependent. In dilute solutions there is an equilibrium between the solvent-separated ion pair and a weak contact ion pair. Higher concentrations of 2a facilitate the formation of a tight ion pair that has a low-frequency isocarbonyl absorption. Remarkably, complexes 1a and 2a are easily transformed in toluene into the two-dimensional sheetlike arrays [(Pyr)(4)Yb[(mu-CO)(2)Co(CO)(2)](2)](infinity) (1b) and [(THF)(2)Yb[(mu-CO)(3)Co(CO)](2).Tol](infinity) (2b). The two-dimensional frameworks are supported by isocarbonyl linkages. Infrared spectra of toluene solutions substantiate the existence of the isocarbonyl bridges with low-frequency absorptions at 1780 cm(-1). Compounds 1b and 2b belong to a rare class of lanthanide-transition-metal carbonyl extended arrays, only three others of which have been structurally established. Dissolving 1b in pyridine regenerates 1a, but the complete conversion of 2b into 2a cannot be achieved. Crystal data: 1a.Pyr is monoclinic, P2(1)/c, a = 11.171(1) A, b = 11.925(1) A, c = 33.978(1) A, beta = 95.10(1) degrees, Z = 4; 2a is monoclinic, C2/c, a = 17.724(1) A, b = 12.468(1) A, c = 18.413(1) A, beta = 100.34(1) degrees, Z = 4; 1b is monoclinic, C2/c, a = 11.047(1) A, b = 13.423(1) A, c = 21.933(1) A, beta = 103.49(1) degrees, Z = 4; 2b is monoclinic, C2/c, a = 28.589(1) A, b = 7.223(1) A, c = 14.983(1) A, beta = 118.90(1) degrees, Z = 4.