胺(或氨) - CHCl3系CT复合物密度泛函法研究

报道对氨(NH3母体)、甲胺(CH3NH2)、二甲胺[(CH3)2NH]、三甲胺[(CH3)3N]与三氯甲烷(CHCl3)形成的系列复合物的理论研究结果。把复合物看作一个超分子,在B3LYP/6-311G(d,p)的水平上进行密度泛函法计算,并运用完全均衡校正法进行基组超位误差校正(BSSE)。探讨该系列复合物的电子结构与相关性质,如稳定性、电荷转移及主要几何参数的变化规律等,结果表明,形成复合物的稳定性次序为NH3－CHCl3(Ⅰ)>CH3NH2-CHCl3(Ⅱ)>(CH3)2NH-CHCl3(Ⅲ)>(CH3)3N-CHCl3(Ⅳ)。形成复合物的过程包含着电荷转移。该系列复合物的稳定性与电荷转移量、前线轨道能量差△εL-H及广义H键距离良好的线性关系,与结合点的电荷布居也有密切的关系,复合物的稳定性是分子间共价作用和静电作用两方面因素综合的结果。计算结果能较好地解释有关的实验现象和规律。     

胺(或氨) - CHCl3系CT复合物密度泛函法研究

报道对氨(NH3母体)、甲胺(CH3NH2)、二甲胺[(CH3)2NH]、三甲胺[(CH3)3N]与三氯甲烷(CHCl3)形成的系列复合物的理论研究结果。把复合物看作一个超分子,在B3LYP/6-311G(d,p)的水平上进行密度泛函法计算,并运用完全均衡校正法进行基组超位误差校正(BSSE)。探讨该系列复合物的电子结构与相关性质,如稳定性、电荷转移及主要几何参数的变化规律等,结果表明,形成复合物的稳定性次序为NH3－CHCl3(Ⅰ)>CH3NH2-CHCl3(Ⅱ)>(CH3)2NH-CHCl3(Ⅲ)>(CH3)3N-CHCl3(Ⅳ)。形成复合物的过程包含着电荷转移。该系列复合物的稳定性与电荷转移量、前线轨道能量差△εL-H及广义H键距离良好的线性关系,与结合点的电荷布居也有密切的关系,复合物的稳定性是分子间共价作用和静电作用两方面因素综合的结果。计算结果能较好地解释有关的实验现象和规律。     

胺(或氨)一CHCI3系CT复合物密度泛函法研究

报道对氨(NH3,母体)、甲胺(CH3NH2)、二甲胺[(CH3)2NH]、三甲胺[(CH3)3N]与三氯甲烷(CHCL3)形成的系列复合物的理论研究结果．把复合物看作一个超分子,在B3LYP/6-311G(d,p)的水平上进行密度泛函法计算,并运用完全均衡校正法进行基组超位误差校正(BSSE).探讨该系列复合物的电子结构与相关性质,如稳定性、电荷转移及主要几何参数的变化规律等.结果表明,形成复合物的稳定性次序为NH3-CHCl3(Ⅰ)>CH3NH2-CHCL3(Ⅱ)>(CH3)2NH-CHCl3(Ⅲ)>(CH3)3N-CHCl3(Ⅳ).形成复合物的过程包含着电荷转移.该系列复合物的稳定性与电荷转移量、前线轨道能量差ΔεL-H及广义H键距离有良好的线性关系,与结合点的电荷布居也有密切的关系.复合物的稳定性是分子间共价作用和静电作用两方面因素综合的结果.计算结果能较好地解释有关的实验现象和规律.     

三硝基苯-对位取代苯酚负离子荷移复合物从头算研究

运用G94W量子化学程序,在HF/3-21G基组水平上对三硝基苯-对位取代苯酚(取代基:CH~3O-,CH~3-,Cl-)负离子的电荷转移复合物进行从头计算。把电荷转移复合物看成一个超分子,研究该系列复合物的稳定性、电荷转移及几何构型等规律。计算结果表明,苯酚负离子供电中心O沿一倾角指向三硝基苯中的任意相邻两个硝基之间的C位置上,复合物的稳定性按对位取代苯酚取代基CH~3O-,CH~3-,Cl-的次序减小,与实验规律相一致。计算结果还表明,形成该系列复合物具有明显的电荷转移,其稳定性与电荷转移量有关等。     

C4H5N-(H2O)n氢键团簇的多光子电离与从头计算研究

在355、532nm激光波长下用TOF质谱研究了C4H5N-(H2O)n氢键团簇体系的多光子电离。二波长下均得到一系列C4H5N-(H2O)n+及质子化产物C4H5N-(H2O)nH+。355nm下可能存在双光子共振电离过程,使得该波长下吡咯母体及团簇离子信号较532nm有明显增强。从头计算结果表明质子化产物的质子更可能连接于吡咯环的α-C原子,而不是N原子上,即光电离过程诱发了一个簇内的质子转移反应。在532nm下质子化产物的生成主要来自于一个发生于团簇内部的Penning电离或电荷转移过程。团簇的形成对吡咯光解产物的稳定化作用使得团簇系列C4H4N-(H2O)n+出现反常强度变化。     

C_4H_4Y(Y=O,S,Se)与BX_3(X=H,F,Cl)作用的计算化学研究

采用量子化学的密度泛函B3LYP和二阶微扰MP2(full)方法对C4H4Y(Y=O,S,Se)与BX3(X=H,F,Cl)形成的电子授受型复合物进行了研究,所得18个复合物的构型包括BX3位于C=C双键上方的π-p作用型和B与O,S,Se直接作用的n-p作用型.体系C4H4Y-BH3以n-p作用型较为稳定,体系C4H4Y-BF3,C4H4Y-BCl3的π-p和n-p作用型复合物稳定性相当.对各复合物的几何构型、振动频率和自然键轨道分析表明,复合物的形成过程中均存在几何构型的改变、电荷的转移和振动频率的变化,它们的变化规律与复合物稳定性的变化规律基本一致,即按H,F,Cl的顺序依次降低.     

吡啶与HCl和CHCl3形成分子间红移氢键和蓝移氢键的理论研究

采用量子化学从头算的MP2方法, 分别在6-31G(d,p), 6-311+G(d,p)和AUG-cc-pVDZ基组下, 研究了复合物C5H5N…HCl(1), C5H5N…HCCl3(2)和C5H5N…HCCl3(3)的分子间氢键. 计算结果表明, 在复合物1中, HCl中Cl—H键伸长, 形成Cl—H…N红移氢键; 在复合物2中, HCCl3中C—H键伸长, 形成C—H…N 红移氢键; 在复合物3中, HCCl3中C—H键收缩, 形成C—H…π蓝移氢键. 自然键轨道(NBO)分析表明, 影响氢键红移和氢键蓝移主要有3个因素: n(Y)→σ*(X—H)超共轭作用、X—H键轨道再杂化和质子供体电子密度重排. 其中, 超共轭作用属于键伸长效应, 电子密度重排和轨道再杂化属于键收缩效应. 在复合物1和2中, 由于键伸长效应处于优势地位导致形成红移氢键; 在复合物3中, 由于键收缩效应处于优势地位导致形成蓝移氢键.     

苯·四氰乙烯电子施受复合物的量子化学研究 Ⅰ.施受体之间的旋转势垒及键型

本文用EHMO方法对C_6H_6·C_2(CN)_4电子施受复合物的电子结构进行了计算,计算时把C_6H_6·C_2(CN)_4看成一个超级分子.计算结果表明,复合物形成的距离3.6A处于能量变化陡峭和趋于平缓的转折点上。室温下C_6H_6平面相对于C_2(CN)_4平面可以自由旋转,自由旋转势垒～0.01kcal/mol,每旋转360°要克服六重势垒.体系能量低的构型是C_2(CN)_4中C—C键与C_6H_6中某一相对C—C键相互垂直的构型,而不是与C_6H_6中某一相对C—C键相互平行的构型、电荷转移随角度而变化与体系能量随角度而变化的倾向相反,能量的极小值对应于电荷转移的极大值.这说明,在此弱电子施受复合物C_6H_6·C_2(CN)_4中电荷转移仍起着决定性的作用。复合物形成时,C_6H_6上的H来参加电荷转移,表征了π-π复合的特性。     

苯酚-酰胺系列氢键复合物从头计算研究

运用G94W量子化学程序包,在HF/6-31G基组水平上对酰胺(DMF,DMA,HCONH2,HCONHCH3andCH3CONH2)与苯酚形成的系列氢键复合物(看作超分子)进行从头计算研究。根据计算结果探讨复合物的稳定性、施体和受体间的电荷转移及几何参数变化等规律。结果表明苯酚与上述一系列酰胺都可形成稳定的氢键复合物,其稳定性次序为CH3CONH2～HCONHCH3＞HCONH2＞DMA＞DMF。结果还表明形成氢键复合物的过程包含着电荷转移,电荷由供体酰胺转移到受体苯酚中,酰胺中C=O键长和苯酚中的O-H键长都明显有规律性地变长。计算结果与实验规律相符。     

OCS,CO2,N2O与烯、炔烃之间π…π作用的电子密度拓扑研究

采用MP2/aug-cc-pVDZ方法对氧硫化碳(OCS)、二氧化碳(CO2)、一氧化二氮(N2O)与乙烯(C2H4)、乙炔(C2H2)、2-丁炔(C4H6)之间形成的平行构型复合物中的分子间相互作用进行了理论研究.复合物的相互作用能按照B…C2H4B…C2H2>B…C4H6(B=OCS,CO2,N2O)的顺序依次减小.采用电子密度拓扑分析理论方法,讨论了复合物中π…π作用的成键特性.电子密度拓扑分析表明复合物中形成了弱的分子间相互作用,且以静电作用为主;π电子密度分子图与全电子密度分子图中键径方向是一致的,说明π…π作用在本文所讨论的体系中起着很重要的作用.NBO分析表明净电荷迁移从电子给体C2H4,C2H2,C4H6到电子受体OCS,CO2,N2O,迁移数按照B…C2H4相似文献   

Metal-promoted aromatic ring amination and deamination reactions at a diazo ligand coordinated to rhodium and ruthenium

Reactions of MCl(3).3H(2)O (M = Rh and Ru) with the ligand 2-[(2-N-arylamino)phenylazo]pyridine [HL(1); NH(4)C(5)N=NC(6)H(4)N(H)C(6)H(4)(H) (HL(1a)), NH(4)C(5)N=NC(6)H(4)N(H)C(6)H(4)(CH(3)) (HL(1b)), and NH(4)C(5)N=NC(6)H(4)N(H)C(5)H(4)N (HL(1c))] in the presence of dilute NEt(3) afforded multiple products. In the case of rhodium, two green compounds, viz. [Rh(L(1))(2)](+) ([2](+)) and [RhCl(pap)(L(1))](+) ([3](+)), where L(1) and pap stand for the conjugate base of [HL(1)] and 2-(phenylazo)pyridine, respectively, were separated on a preparative thin layer chromatographic plate. The reaction of RuCl(3).3H(2)O, on the other hand, produced two brown compounds, viz. [RuCl(HL(1))(L(1))] (4) and [RuCl(pap)(L(1))] (5), respectively, as the major products. The X-ray structures of the representative complexes are reported. Except for complex 2, and 4, the products are formed due to the cleavage of an otherwise unreactive C(phenyl)-N(amino) bond. In complex 4, one of the tridentate ligands (HL(1)) does not use its maximum denticity and coordinates as a neutral bidentate donor. Plausible reasons for the differences in their modes of coordination of the ligands as in 2 and 4 have been discussed. The ligand pap in the cationic mixed ligand complex [3](+) reacts instantaneously with ArNH(2) to produce an ink-blue compound, [RhCl(HL(2))(L(1))](+) ([6](+)) in a high yield. The ligand HL(2) is formed due to regioselective fusion of ArNH(2) residue at the para carbon of the phenyl ring (with respect to the azo fragment) of pap in [3](+). The above complexes are generally intensely colored and show strong absorptions in the visible region, which are assigned to intraligand charge transfer transitions. These complexes undergo multiple and successive one-electron-transfer processes at the cathodic potentials. Electrogenerated cationic complexes of ruthenium(III), [4](+) and [5](+), showed rhombic EPR spectra at 77 K.     

Preparations, structures, and electrochemical studies of aryldiazene complexes of rhenium: syntheses of the first heterobinuclear and heterotrinuclear derivatives with bis(diazene) or bis(diazenido) bridging ligands

The mono- and binuclear aryldiazene complexes [Re(C6H5N=NH)(CO)5-nPn]BY4 (1-5) and [(Re(CO)5-nPn)2-(mu-HN=NAr-ArN=NH)](BY4)2 (6-12) [P = P(OEt)3, PPh(OEt)2, PPh2OEt; n = 1-4; Ar-Ar = 4,4'-C6H4-C6H4, 4,4'-(2-CH3)C6H3-C6H3(2-CH3), 4,4'-C6H4-CH2-C6H4; Y = F, Ph) were prepared by reacting the hydride species ReH(CO)5-nPn with the appropriate mono- and bis(aryldiazonium) cations. These compounds, as well as other prepared compounds, were characterized spectroscopically (IR; 1H, 31P, 13C, and 15N NMR data), and 1a was also characterized by an X-ray crystal structure determination. [Re(C6H5N=NH)(CO)(P(OEt)3)4]BPh4 (1a) crystallizes in space group P1 with a = 15.380(5) A, b = 13.037(5) A, c = 16.649(5) A, alpha = 90.33(5) degrees, beta = 91.2(1) degrees, gamma = 89.71(9) degrees, and Z = 2. The "diazene-diazonium" complexes [M(CO)3P2(HN=NAr-ArN identical to N)](BF4)2 (13-15, 17) [M = Re, Mn; P = PPh2OEt, PPh2OMe, PPh3; Ar-Ar = 4,4'-C6H4-C6H4, 4,4'-C6H4-CH2-C6H4] and [Re(CO)4(PPh2OEt)(4,4'-HN=NC6H4-C6H4N identical to N)](BF4)2 (16b) were synthesized by allowing the hydrides MH(CO)3P2 or ReH(CO)4P to react with equimolar amounts of bis(aryldiazonium) cations under appropriate conditions. Reactions of diazene-diazonium complexes 13-17 with the metal hydrides M2H2P'4 and M2'H(CO)5-nP"n afforded the heterobinuclear bis(aryldiazene) derivatives [M1(CO)3P2(mu-HN=NAr-ArN=NH)M2HP'4](BPh4)2 (ReFe, ReRu, ReOs, MnRu, MnOs) and [M1(CO)3P2(mu-HN=NAr-ArN=NH)M2'(CO)5-nP"n](BPh4)2 (ReMn, MnRe) [M1 = Re, Mn; M2 = Fe, Ru, Os; M2' = Mn, Re; P = PPh2OEt, PPh2OMe; P',P" = P(OEt)3, PPh(OEt)2; Ar-Ar = 4,4'-C6H4-C6H4, 4,4'-C6H4-CH2-C6H4; n = 1, 2]. The heterotrinuclear complexes [Re(CO)3(PPh2OEt)2(mu-4,4'-HN=NC6H4-C6H4N=NH)M(P(OEt)3)4(mu-4,4'-HN=NC6H4- C6H4N=NH)Mn(CO)3(PPh2OEt)2](BPh4)4 (M = Ru, Os) (ReRuMn, ReOsMn) were obtained by reacting the heterobinuclear complexes ReRu and ReOs with the appropriate diazene-diazonium cations. The heterobinuclear complex with a bis(aryldiazenido) bridging ligand [Mn(CO)2(PPh2OEt)2(mu-4,4'-N2C6H4-C6H4N2)Fe(P(OEt)3)4]BPh4 (MnFe) was prepared by deprotonating the bis(aryldiazene) compound [Mn(CO)3(PPh2OEt)2(mu-4,4'-HN=NC6H4-C6H4N=NH)Fe(4- CH3C6H4CN)(P(OEt)3)4](BPh4)3. Finally, the binuclear compound [Re(CO)3(PPh2OEt)2(mu-4,4'-HN=NC6H4-C6H4N2)Fe(CO)2(P(OPh)3)2](BPh4)2 (ReFe) containing a diazene-diazenido bridging ligand was prepared by reacting [Re(CO)3(PPh2OEt)2(4,4'-HN=NC6H4-C6H4N identical to N)]+ with the FeH2(CO)2(P(OPh)3)2 hydride derivative. The electrochemical reduction of mono- and binuclear aryldiazene complexes of both rhenium (1-12) and the manganese, as well as heterobinuclear ReRu and MnRu complexes, was studied by means of cyclic voltammetry and digital simulation techniques. The electrochemical oxidation of the mono- and binuclear aryldiazenido compounds Mn(C6H5N2)(CO)2P2 and (Mn(CO)2P2)2(mu-4,4'-N2C6H4-C6H4N2) (P = PPh2OEt) was also examined. Electrochemical data show that, for binuclear compounds, the diazene bridging unit allows delocalization of electrons between the two different redox centers of the same molecule, whereas the two metal centers behave independently in the presence of the diazenido bridging unit.     

Synthesis, structural characterization, antimicrobial and cytotoxic effects of aziridine, 2-aminoethylaziridine and azirine complexes of copper(II) and palladium(II)

The synthesis, spectroscopic and X-ray structural characterization of copper(II) and palladium(II) complexes with aziridine ligands as 2-dimethylaziridine HNCH(2)CMe(2) (a), the bidentate N-(2-aminoethyl)aziridines C(2)H(4)NC(2)H(4)NH(2) (b) or CH(2)CMe(2)NCH(2)CMe(2)NH(2) (c) as well as the unsaturated azirine NCH(2)CPh (d) are reported. Cleavage of the cyclometallated Pd(II) dimer [μ-Cl(C(6)H(4)CHMeNMe(2)-C,N)Pd](2) with ligand a yielded compound [Cl(NHCH(2)CMe(2))(C(6)H(4)CHMe(2)NMe(2)-C,N)Pd] (1a). The reaction of the aziridine complex trans-[Cl(2)Pd(HNC(2)H(4))(2)] with an excess of aziridine in the presence of AgOTf gave the ionic chelate complex trans-[(C(2)H(4)NC(2)H(4)NH(2)-N,N')(2)Pd](OTf)(2) (2b) which contains the new ligand b formed by an unexpected insertion and ring opening reaction of two aziridines ("aziridine dimerization"). CuCl(2) reacted in pure HNC(2)H(4) or HNCH(2)CMe(2) (b) again by "dimerization" to give the tris-chelated ionic complex [Cu(C(2)H(4)NC(2)H(4)NH(2)-N,N')(3)]Cl(2) (3b) or the bis-chelated complex [CuCl(C(2)H(2)Me(2)NC(2)H(2)Me(2)NH(2)-N,N')(2)]Cl (4c). By addition of 2H-3-phenylazirine (d) to PdCl(2), trans-[Cl(2)Pd(NCH(2)CPh)(2)] (5d) was formed. All new compounds were characterized by NMR, IR and mass spectra and also by X-ray structure analyses (except 3b). Additionally the cytotoxic effects of these complexes were examined on HL-60 and NALM-6 human leukemia cells and melanoma WM-115 cells. The antimicrobial activity was also determined. The growth of Gram-positive bacterial strains (S. aureus, S. epidermidis, E. faecalis) was inhibited by almost all tested complexes at the concentrations of 37.5-300.0 μg mL(-1). However, MIC values of complexes obtained for Gram-negative E. coli and P. aeruginosa, as well as for C. albicans yeast, mostly exceeded 300 μg mL(-1). The highest antibacterial activity was achieved by complexes 1a and 2b. Complex 2b also inhibited the growth of Gram-negative bacteria.     

Cyclo- and carbophosphazene-supported ligands for the assembly of heterometallic (Cu2+/Ca2+, Cu2+/Dy3+, Cu2+/Tb3+) complexes: synthesis, structure, and magnetism

The carbophosphazene and cyclophosphazene hydrazides, [{NC(N(CH(3))(2))}(2){NP{N(CH(3))NH(2)}(2)}] (1) and [N(3)P(3)(O(2)C(12)H(8))(2){N(CH(3))NH(2)}(2)] were condensed with o-vanillin to afford the multisite coordination ligands [{NC(N(CH(3))(2))}(2){NP{N(CH(3))N═CH-C(6)H(3)-(o-OH)(m-OCH(3))}(2)}] (2) and [{N(2)P(2)(O(2)C(12)H(8))(2)}{NP{N(CH(3))N═CH-C (6)H(3)-(o-OH)(m-OCH(3))}(2)}] (3), respectively. These ligands were used for the preparation of heterometallic complexes [{NC(N(CH(3))(2))}(2){NP{N(CH(3))N═CH-C(6)H(3)-(o-O)(m-OCH(3))}(2)}{CuCa(NO(3))(2)}] (4), [{NC(N(CH(3))(2))}(2){NP{N(CH(3))N═CH-C(6)H(3)-(o-O)(m-OCH(3))}(2)}{Cu(2)Ca(2)(NO(3))(4)}]·4H(2)O (5), [{NC(N(CH(3))(2))}(2){NP{N(CH(3))N═CH-C(6)H(3)-(o-O)(m-OCH(3))}(2)}{CuDy(NO(3))(4)}]·CH(3)COCH(3) (6), [{NP(O(2)C(12)H(8))}(2){NP{N(CH(3))N═CH-C(6)H(3)-(o-O)(m-OCH(3))}(2)}{CuDy(NO(3))(3)}] (7), and [{NP(O(2)C(12)H(8))}(2){NP{N(CH(3))N═CH-C(6)H(3)-(o-O)(m-OCH(3))}(2)}{CuTb(NO(3))(3)}] (8). The molecular structures of these compounds reveals that the ligands 2 and 3 possess dual coordination pockets which are used to specifically bind the transition metal ion and the alkaline earth/lanthanide metal ion; the Cu(2+)/Ca(2+), Cu(2+)/Tb(3+), and Cu(2+)/Dy(3+) pairs in these compounds are brought together by phenoxide and methoxy oxygen atoms. While 4, 6, 7, and 8 are dinuclear complexes, 5 is a tetranuclear complex. Detailed magnetic properties on 6-8 reveal that these compounds show weak couplings between the magnetic centers and magnetic anisotropy. However, the ac susceptibility experiments did not reveal any out of phase signal suggesting that in these compounds slow relaxation of magnetization is absent above 1.8 K.     

Imidomolybdenum(IV) porphyrin complexes: synthesis, characterization, and intermetal imido transfer reactivity

The imido(meso-tetra-p-tolylporphyrinato)molybdenum(IV) complexes, (TTP)Mo=NR, where R = C6H5 (1a), p-CH3C6H4 (1b), 2,4,6-(CH3)3C6H2 (1c), and 2,6-(i-Pr)2C6H4 (1d), can be prepared by the reaction of (TTP)MoCl2 with 2 equiv of LiNHR in toluene. Upon treatment of the imido complexes with pyridine derivatives, NC5H4-p-X (X = CH3, CH(CH3)2, C[triple bond]N), new six-coordinate complexes, (TTP)Mo=NR.NC5H4-p-X, were observed. The reaction between the molybdenum imido complexes, (TTP)Mo=NC6H5 or (TTP)Mo=NC6H4CH3, and (TTP)Ti(eta2-PhC[triple bond]CPh) resulted in complete imido group transfer and two-electron redox of the metal centers to give (TTP)Mo(eta2-PhC[triple bond]CPh) and (TTP)Ti=NC6H5 or (TTP)Ti=NC6H4CH3.     

Synthesis, spectroscopic, electrochemical and Pb2+-binding studies of tetrathiafulvalene acetylene derivatives

A series of tetrathiafulvalene acetylene derivatives, [TTF-Ctriple bondC-A] [A=C6H4N(CH3)2-4 (1), C6H4OCH3-4 (2), C6H5 (3), C6H4F-4 (4), C6H4NO2-4 (5), C5H4N-2 (6), C5H4N-3 (7), and C5H4N-4 (8)], have been designed and synthesized to provide insight into the nature of the donor-acceptor interaction via a pi-conjugated triple bond. The X-ray crystal structure of [TTF-(Ctriple bondC)-C6H4OCH3-4] (2) reveals that the phenyl ring linked by acetylene is almost coplanar to the plane of TTF with a dihedral angle of 3.6 degrees. The strong intermolecular C-H...O hydrogen bonding was found to direct the molecular helical assemblies with a screw pitch of 5.148 A when viewed along the a-axis. Spectroscopic and electrochemical behaviors of the tetrathiafulvalene acetylene derivatives demonstrate that the TTF unit interacts with the electron-accepting group through the triple bond, thus leading to the intramolecular charge transfer. The pyridine-substituted TTF compounds 6-8 show remarkable sensing and coordinating properties toward Pb2+. Comparison of the spectroscopic and electrochemical properties and the calculation at the B3LYP/6-31G* level available in Gaussian 03 reveals that varying the bridged unit of the TTF-pi-A system from a double bond to a triple bond leads to positive shifts for the first and second oxidation potentials of the TTF moieties, while the extent of intramolecular charge transfer interactions through the pi-conjugated triple bond is smaller than that through the double bond.     

Synthesis and Characterization of Ferrocene—Containing Liquid Crystalline Materials with a Bromo—phenyl Moiety

Ten ferrocene-containing liquid crystalline materials,pFcC6H4CO2C6H4N-CHC6H4O2CC6H3BrOCnH2n 1(type I)and p-FcC6H4N=CHC6H4O2CC6H3BrOCnH2n 1(type II),were synthesized by condensation reactions of two ferrocenesubstituted amines,p-FcC6H4CO2C6H4NH2(4)and pFcC6H4NH2(5)(Fc:ferrocenyl)with five bromo-substituted benzaldehydes(3)(H2n 1CnOC6H3BrCOOC6H4CHO,n=2,4,6,8and 10).Their mesogenic behaviors were studied by hot-stage polarized optical microscopy and differential scanning calorimetry,The effects of structure(rigid core,terminal chain length)on the phase transition behaviors were discussed.     

New highly stable metallabenzenes via nucleophilic aromatic substitution reaction

Treatment of the ruthenabenzene [Ru{CHC(PPh(3))CHC(PPh(3))CH}Cl(2)(PPh(3))(2)]Cl (1) with excess 8-hydroxyquinoline in the presence of CH(3)COONa under air atmosphere produced the S(N)Ar product [(C(9) H(6)NO)Ru{CHC(PPh(3))CHC(PPh(3))C}(C(9)H(6)NO)(PPh(3))]Cl(2) (3). Ruthenabenzene 3 could be stable in the solution of weak alkali or weak acid. However, reaction of 3 with NaOH afforded a 7:1 mixture of ruthenabenzenes [(C(9)H(6)NO)Ru{CHC(PPh(3))CHCHC}(C(9)H(6)NO)(PPh(3))]Cl (4) and [(C(9)H(6)NO)Ru{CHCHCHC(PPh(3))C}(C(9)H(6)NO)(PPh(3))]Cl (5), presumably involving a P-C bond cleavage of the metallacycle. Complex 3 was also reactive to HCl, which results in a transformation of 3 to ruthenabenzene [Ru{CHC(PPh(3))CHC(PPh(3))C}Cl(2)(C(9)H(6)NO)(PPh(3))]Cl (6) in high yield. Thermal stability tests showed that ruthenabenzenes 4, 5, and 6 have remarkable thermal stability both in solid state and in solution under air atmosphere. Ruthenabenzenes 4 and 5 were found to be fluorescent in common solvents and have spectral behaviors comparable to those organic multicyclic compounds containing large π-extended systems.     

Synthesis, characterization, and catalytic activity of rare earth metal amides supported by a diamido ligand with a CH2SiMe2 link

A series of four coordinate rare earth metal amides with general formula ((CH2SiMe2)[(2,6- IPr2C6H3)N]2)LnN(SiMe3)2(THF) [(Ln = Yb(2), Y (3), Dy (4), Sm (5), Nd (6)] containing a diamido ligand (CH2SiMe2)[(2,6-iPr2C6H3)N]2(2-) with a CH2SiMe2 link were synthesized in good yields via reaction of [(Me3Si)2N]3Ln(III)(mu-Cl)Li(THF)3 with the corresponding diamine (CH2SiMe2)[(2,6-iPr2C6H3)NH]2 (1). All compounds were fully characterized by spectroscopic methods and elemental analyses. The structures of complexes 2, 3, 4, 5, and 6 were determined by single-crystal X-ray analyses. Investigation of the catalytic properties of the complexes indicated that all complexes exhibited a high catalytic activity on the cyclotrimerization of aromatic isocyanates, which represents the first example of cyclopentadienyl-free rare earth metal complexes exhibiting a high catalytic activity and a high selectivity on cyclotrimerization of aromatic isocyanates. The temperatures, solvents, catalyst loading, and the rare earth metal effects on the catalytic activities of the complexes were examined.     

Reversible and selective amine interactions of [Cd(mu2-N,O-p-NH2C6H4SO3)2(H2O)2]n

[Cd(mu2-N,O-p-NH2C6H4SO3)2(H2O)2]n (1) is a layered coordination compound. The solid-vapor reactions between crystalline 1 and a series of volatile amines were investigated and the corresponding amine adducts were characterized by EA, TGA, PXRD and IR. Among them, the C2H5NH2 and C3H7NH2 adducts, namely [Cd(C2H5NH2)4(H2O)2](H2NC6H4SO3)2 (3) and [Cd(C3H7NH2)4(O-p-H2NC6H4SO3)2].C3H7NH2 (4), grew into single crystals in situ from the solid-vapor reaction processes and their crystal structures were characterized. In both cases, 4 mol equiv. of amine molecules coordinate to Cd(II) via replacing the N,O-p-NH2C6H4SO3 ligands or coordinated water molecules. The single-phase product suggests that the solid-vapor reaction between the metal sulfonate and volatile alkylamines could be used as a green process to synthesize monoamine-coordinated Cd(II) complexes without any solvent and routine separation. Finally, the substitution reaction is reversible at room conditions and selective for primary alkylamines.