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1.
The reaction of N‐aryl benzamidines 1a , 1b , 1c , 1d , 1e , 1f , 1g , 1h , 1i , 1j , 1k , 1l , 1m , 1n with diphenyl carbonate 2a or ethyl phenyl carbonate 2b synthesized 2‐arylquinazolin‐4(3H)‐ones 3a , 3b , 3c , 3d , 3e , 3f , 3g , 3h , 3i , 3j , 3k , 3l , 3m , 3n in simple and safe process with good yields (71–90%). It was suggested that different electron‐donating substituent in N‐aryl benzamidines 1a , 1b , 1c , 1d , 1e , 1f , 1g , 1h , 1i , 1j , 1k , 1l , 1m , 1n afforded similar effect to the yields of 2‐arylquinazolin‐4(3H)‐ones 3a , 3b , 3c , 3d , 3e , 3f , 3g , 3h , 3i , 3j , 3k , 3l , 3m , 3n . In these reactions, N‐aryl benzamidines 1a , 1b , 1c , 1d , 1e , 1f , 1g , 1h , 1i , 1j , 1k , 1l , 1m , 1n built up intermediate compounds by nucleophilic addition to carbonates 2 to give annulation products 3a , 3b , 3c , 3d , 3e , 3f , 3g , 3h , 3i , 3j , 3k , 3l , 3m , 3n , following to cyclization involving the elimination of ethanol/phenol.  相似文献   

2.
The extensive search for the global minimum structure of Hf3 at the B3LYP/LANL2DZ level of theory revealed that D3h 3A2' (1a1'(2)1a2'(2)1e'(4)2a1'(2)1e'2) and D3h 1A1' (1a1'(2)2a1'(2)1e'(4)1a2'(2)3a1'2) are the lowest triplet and singlet states, respectively, with the triplet state being the lowest one. However, at the CASSCF(10,14)/Stuttgart+2f1g level of theory these two states are degenerate, indicating that at the higher level of theory the singlet state could be in fact the global minimum structure. The triplet D3h 3A2' (1a1'21a2'(2)1e'(4)2a1'(2)1e'2) structure is doubly (sigma- and pi-) aromatic and the singlet D3h 1A1' (1a1'(2)2a1'(2)1e'(4)1a2'(2)3a1'2) structure is the first reported triply (sigma-, pi-, and delta-) aromatic system.  相似文献   

3.
Syntheses of Some Alkyl, Cycloalkyl and Aryl 3-Aminophenyl Sulfones Syntheses of alkyl ( 1a – 1i, 1m ), cycloalkyl ( 1j, 1k ) and aryl ( 1l ) 3-aminophenyl sulfones were achieved by ethanolic Béchamp-reduction of the appropriate 3-nitrophenyl sulfones ( 3a – 3m ). The alkyl ( 3a – 3i ) and cycloalkyl ( 3j, 3k ) 3-nitrophenyl sulfones were prepared via nitration of their respective sulfones ( 2a – 2k ). Methyl (3-nitrophenyl) sulfone ( 3a ) was also prepared by condensation of 3-nitrobenzenesulfinic acid ( 4 ) with bromoacetic acid to 3-nitrophenylsulfonyl-acetic acid ( 5 ) followed by decarboxylation.  相似文献   

4.
Large-scale MRD CI calculations assign to AlP the ground state X 3Σ (9σ22) and a close-lying state 1 3Π (9σ3π3) (Te = 0.08 eV). Up to transition energies of 2.0 eV, other states are described by the configurations 9σ3π3 (11Π), 8σ24 (1 1Σ+), 9σ22 (1 1Δ and 2 1Σ+) and 9σ3π24π (1 5Π). The 2 3Π state, located at ≈ 2.30 eV, shows a shallow double minimum. Numerous perturbations are expected to induce predissociation upon 2 3Π. Multiplets arising from the occupation 8σ234π are clustered in the 3.25–3.50 eV region. Quintet states with the configuration 8σ9σ3π34π are bound, with Te values (in eV) of 3.80 (1 5Σ+), 4.44 (1 5Δ) and 4.88 (3 5Σ), respectively. The 9σ → 4s Rydberg members 5Σ and 3Σ lie in the 4.58–4.72 eV energy region. The first ionization potential (ionization to X4Σ of AlP+, 9σ → ∞) is estimated to be 7.65 eV. Ionization to the 1 2Σ and 1 2Π states of AlP+ is suggested to occur between 8.0 and 8.8 eV. The dipole moments of X 3Σ, 1 1Δ and 2 1Σ+ are close to 1.0 D, whereas the 1 1Σ+ state has μ = 3.49 D; 1 3Π and 1 1Π have dipole moments from 2.45 to 2.91 D. All low-lying states show a polarity Al+P. Finally, the electronic structure and transition energies of AlP are compared with those of the isoelectronic species BN, AIN, and SiP+.  相似文献   

5.
以共沉淀法合成的前驱体Ni1/3Co2/3-xAlx(OH)2与低共熔锂盐0.38LiOH·H2O-0.62LiNO3制备了锂离子电池正极材料LiNi1/3Co2/3-xAlxO2(x=1/12,1/6,1/3,1/2,7/12).采用X射线衍射(XRD)、扫描电镜(SEM)和电化学性能测试对其结构、形貌和电化学性质进行表征.结果表明,LiNi1/3Co2/3-xAlxO2在1/12≤x≤1/3范围内可以保持单一的六方层状α-NaFeO2结构,当Al掺杂量(x)高于1/3时,会出现杂相.其中,LiNi1/3Co1/3Al1/3O2结晶程度最高,阳离子混排效应最小,并且颗粒小而均匀,振实密度可以达到2.88g·cm-3,首次放电容量为151.5mAh·g-1,循环50次后放电容量保持在91.4%,在1C和2C倍率下放电容量仍可达到133.7和120.9mAh·g-1.  相似文献   

6.
A novel reaction of α-iodo ketone (α-iodocycloalkanone, α-iodo-β-alkoxy ester, and α-iodoacyclicketone) with irradiation under a high-pressure mercury lamp gave the corresponding α-hydroxyketone in good yields. In the case of α,α′-diiodo ketone, α,α′-dihydroxyketone which little has been reported until now was obtained. This reaction affords a new, clean and convenient synthetic method for α-hydroxy- and α,α′-dihydroxyketone.  相似文献   

7.
The products of bromo and chlorofluorination of E and Z-1,2-dichloroethylenes, 1, 3-dichloro-1-propenes, 1, 1-dichloro- ethylene and 1, 3-dichloro-2-fluoro-1-propene by N-bromosuccinimide and hexachloromelamine in anhydrous hydrogen fluoride have been studied. It was found that the reaction was in all cases 100% regio and 93–100% trans-stereospecific with the exception of E-1, 2-dichloro-ethylene, its trans-stereospecificity being 85%.Threo and erithro-1-bromo-1, 2-dichloro-2-fluoroethanes, 2-bromo-1, 3-dichloro-1-fluoropropanes and 1, 2, 3-trichloro-1-fluoro-propanes as well 1, 1, 2-trichloro-2-fluoroethane, 1-bromo-2, 2-dichloro-2-fluoroethane, 1, 2, 2-trichloro-2 fluoroethane, 1-bromo-1, 3-dichloro-2, 2-difluoropropane, and 1, 1, 3-trichloro-2,2-difluoropropane were obtained in 50–70% yield.The bromination of E and Z-1, 3-dichloro-1-propenes with molecular bromine in carbon tetrachloride in the dark is non-stereospecific and gives a mixture of erithro and threo-1, 2-dibromo-1, 3-dichloropropanes in the ratio about 1:1. However, the bromination reaction in anhydrous hydrogen fluoride solution proceeds with a high degree of stereospecificity (94–95%) and gives threo-1, 2-dibromo-1, 3-dichloropropane from Z and erithro-1, 2-dibromo-1, 3-dichloropropane from E-1, 3-dichloro-1-propene.The data obtained are considered in terms of an electrophilic mechanism of halogenoalkene halogenation in anhydrous hydrogen fluoride and a free-radical mechanism in carbon tetrachloride.  相似文献   

8.
Medium-resolution spectra of the N2 b1Πu-X1Σg+ band system were recorded by 1 + 1 multiphoton ionization. In the spectra we found different linewidths for transitions to different vibrational levels in the b 1Πu state: Δν0 = 0.50 ± 0.05 cm−1, Δν1 = 0.28 ± 0.02 cm−1, Δν2 = 0.65 ± 0.06 cm−1, Δν3 = 3.2 ± 0.5 cm−1, Δν4 = 0.60 ± 0.07 cm−1, and Δν5 = 0.28 ± 0.02 cm−1. From these linewidths, predissociation lifetimes τν were obtained: τ0 = 16 ± 3 ps, τ1 > 150 ps, τ2 = 10 ± 2 ps, τ3 = 1.6 ± 0.3 ps, τ4 = 9 ± 2 ps, and τ5 > 150 ps. Band origins and rotational constants for the b 1Πuν = 0 and 1 levels were determined for the 14N2 and 14N15N molecules.  相似文献   

9.
In this paper, we report the enantioselective formation of a dynamic noncovalent double rosette assembly 1a(3).(CYA)(6) composed of three 2-pyridylcalix[4]arene dimelamines (1a) and six butylcyanuric acid molecules (BuCYA). The six 2-pyridyl functionalities of the assembly interact stereoselectively with chiral dicarboxylic acids 3a-e via two-point hydrogen-bonding interactions. One of the two enantiomeric assemblies (P- or M-) 1a(3).(CYA)(6) is formed in excess as the result of the complexation of the chiral diacids, resulting in formation of optically active assemblies. The complexations with dibenzoly tartaric acids D-3a and L-3a (3 equivalent), respectively, leading to the formation of diastereomeric assemblies (P)-1a(3).(BuCYA)(6).(D-3a)(3) and (M)-1a(3).(BuCYA)(6).(L-3a)(3) with 90% diastereomeric excess. The diastereomeric excess in (M)-1a(3).(BuCYA)(6).(L-3a)(3) is "memorized" when L-3a is removed by precipitation with ethlylenediamine (EDA). The assembly (M)-1a(3).(BuCYA)(6) is still optically active (90% enantiomeric excess), although none of its individual components are chiral. (M)-1a(3).(BuCYA)(6) has a high kinetic stability toward racemization (E(a) = 119 kJ mol(-)(1), half-life of (M)-1a(3).(BuCYA)(6) is ca. 1 week at 20 degrees C).  相似文献   

10.
王萌  吴锋  苏岳锋  陈实 《物理化学学报》2008,24(7):1175-1179
通过在硝酸钇水溶液浸渍并焙烧的简单工艺, 在LiCo1/3Ni1/3Mn1/3O2材料表面包覆了一层Y2O3. 采用X射线衍射(XRD), 扫描电子显微镜(SEM), 透射电子显微镜(TEM), 循环伏安(CV)和恒流充放电对包覆和未包覆的LiCo1/3Ni1/3Mn1/3O2进行了测试分析. 结果表明, Y2O3包覆并没有改变LiCo1/3Ni1/3Mn1/3O2的晶体结构, 只存在于LiCo1/3Ni1/3Mn1/3O2的表面; 与未包覆的材料相比, Y2O3包覆后的材料在高电位下具有更好的容量保持率和放电容量. CV测试表明, 包覆层的存在有效抑制了材料层状结构的转变及电极与电解液的负反应.  相似文献   

11.
When thienyl Schiff base 1, derived from 2-formylthiophene and hydrazine, reacted with Fe2(CO)9 in n-hexane, three major complexes were obtained: (1) a diironhexacarbonyl complex with two 2-thienylmethylideneamido bridging ligands 2, which resulted from the =N---N= bond cleavage of ligand 1; (2) a doubly cyclometalated di-μ-di-(η12-thienyl; η11(N))bis(hexacarbonyldiiron) complex (3); and (3) a cyclometalated (μ-η12-thienyl; η11(N))hexacarbonyldiiron complex (4). Molecular structures of compounds 1a, 1c, and 2a have been determined by single-crystal X-ray diffraction.  相似文献   

12.
The radiative lifetimes of the b1Σ+ and a1Δ states have been evaluated by perturbation expansions including X3Σ, a1Δ, b1Σ+, 13,1Π, 23,1Π, 23Σ and 21Σ+ states. All wavefunctions result from large MRD CI calculations. The b—X transition is dominated by the parallel transition moment; it is found to be much stronger than the a—X transition. The calculated radiative lifetimes of τ(1Σ+)=18 ms, τ(1Δ)=2.2 s for NF and τ(1Σ+)=2.5–3.5 ms for NCl are in good accord with corresponding experimentally deduced values. The lifetime for the a1Δ state in NCl is found to be τ(1Δ)=1.1 s, ie. much longer than derived from a recent experiment. Its magnitude is consistent with the τ(b1Σ+)/τ(a1Δ) ratio of similar systems and with the decrease in lifetime from NF to NCl and is thus believed to be quite reliable. A detailed analysis of all contributions of the perturber states to the transition mechanism is made and comparison with the related data in SO, O2 and S2 is undertaken. The b-a transition probability dominated by the quadrupole transition is fairly constant in all the systems in the order of A = 0.013 (NF) - 0.0013 (S2) s−1.  相似文献   

13.
Photochromic performance of diarylethene single crystals was controlled by crystal engineering using non-covalent aromatic-aromatic interactions as the directional intermolecular force. A diarylethene derivative with two pentafluorophenyl groups, 1,2-bis(2-methyl-5-pentafluorophenyl-3-thienyl)perfluorocyclopentene (1a), formed stoichiometric co-crystals with benzene (Bz) and naphthalene (Np) by aryl-perfluoroaryl interactions. Face-to-face pi-stacking interactions between the pentafluorophenyl groups of 1a and the aromatic molecules are responsible for 2:1 and 1:1 stoichiometric compositions in 1a/Bz and 1a/Np co-crystals, respectively. The diarylethene underwent thermally stable and photoreversible photochromic reactions in a homo-crystal of 1a and co-crystals 1a/Bz and 1a/Np. The absorption spectra of the photogenerated closed-ring isomers varied depending on the conformation of the diarylethene molecules packed in the crystals. The diarylethene 1a also formed 1:1 stoichiometric co-crystals with different kinds of diarylethenes, 1,2-bis(2-ethyl-5-phenyl-3-thienyl)perfluorocyclopentene (2a) and 1,2-bis[2-methyl-5-(1-naphthyl)-3-thienyl]perfluorocyclopentene (3a). Both co-crystals 1a/2a and 1a/3a showed photochromism. Although 1a, 2a, and 3a underwent efficient photocyclization reactions in their homo-crystals, highly selective photocyclization reactions of 2a or 3a were observed in the co-crystals. The selective reactions were confirmed by HPLC and X-ray crystallography. Excited energy transfers from 1a to 2a and from 1a to 3a are considered to occur and cause the selective reactions.  相似文献   

14.
Cholest-5en-3β-ol 1 , 3,3-ethylenedioxy-androst-4-en-17β-ol 2 and 17,17-ethylenedioxy-1,3,5(10)-estratrien-3β-ol 3 were converted into ethyl ester 1a, 2a and 3a by reaction with ethyl chloroacetate in the presence of potassium. The ethyl esters 1a, 2a and 3a on reaction with hydrazine gave hydrazides 1b, 2b and 3b , which on reaction with cyanogen bromide afforded 1,3,4-oxadiazoles 1c, 2c and 3c .  相似文献   

15.
The new complexes trans-[a2Pt(Hpymo-N1)2]X2 (a = NH3, X = NO3 (1a); a = CH3NH2, X = NO3 (1b); a = CH3NH2, X = ClO4 (1c); Hpymo = 2-hydroxypyrimidine) have been prepared by reaction of trans-[a2Pt(H2O)2]-X2 with 2-hydroxypyrimidine at 80 degrees C in water. Complex 1c cocrystallizes in water with 2-aminopyrimidine (ampym) through formation of complementary pairs of hydrogen bonds to give the supramolecular hexagon [trans-[(CH3NH2)2Pt(pymo-N1)(Hpymo-N1)].Hampym[2(ClO4)4 (2). Molecular recognition of ampym by 1c is responsible for a conformational change of the two hydroxypyrimidine ligands in 1c from anti (1c) to syn and in addition for a proton transfer from a Hpymo residue to ampym against 1.5 units of pKa gradient. 1H NMR concentration-dependent studies as well as NOE experiments in dmso-d6 and dmf-d7 show that 2 dissociates in solution. Compound 1a reacts in NH3:H2O (1:3) with AgI to give the polymeric species [trans-[(NH3)2Pt(mu-pymo-N1,N3)2Ag(H2O)]-NO3]n (3). In contrast to 2, in the polymeric structure the trans-[NH3)2Pt(pymo)2] entities adopt an anti conformation. Nevertheless, the [(H2O)Ag(pymo)2] residues present a syn conformation that leads to a meander-like global structure. Compounds 1b, 1c, 2, and 3 have been studied by X-ray crystallography: (1b) triclinic space group, P1, a = 9.300(2) A, b = 10.483(2) A, c = 11.050(2) A, alpha = 68.21(3) degrees, beta = 75.47(3) degrees, gamma = 73.83(3) degrees, Z = 2, R1 = 0.025, and wR2 = 0.062; (1c) triclinic space group, P1, a = 5.692(1) A, b = 7.758(2) A, c = 11.236(2) A, alpha = 93.12(3) degrees, beta = 92.86(3) degrees, gamma = 102.58(3) degrees, Z = 2, R1 = 0.048, and wR2 = 0.119; (2) triclinic space group, P1, a = 8.355(2) A, b = 11.221(2) A, c = 13.004(3) A, alpha = 86.76(3) degrees, beta = 78.62(3) degrees, gamma = 77.96(3) degrees, Z = 2, R1 = 0.033, and wR2 = 0.080; (3) monoclinic space group, C2/c, a = 5.345(1) A, b = 23.998(5) A, c = 12.474(2) A, beta = 102.27(3) degrees, Z = 8, R1 = 0.041, and wR2 = 0.093.  相似文献   

16.
以过渡金属乙酸盐和乙酸锂为原料,柠檬酸为螯合剂,通过溶胶-凝胶法结合高温煅烧法制备了锂离子电池富锂锰基正极材料xLi2MnO3·(1-x)Li[Ni1/3Mn1/3Co1/3]O2,采用X射线衍射(XRD),扫描电子显微镜(SEM)和电化学性能测试对所得样品的结构,形貌及电化学性能进行了表征.结果表明:x=0.5时,在900°C下煅烧12h得到颗粒均匀细小的层状xLi2MnO3·(1-x)Li[Ni1/3Mn1/3Co1/3]O2材料,并具有良好的电化学性能,在室温下以20mA·g-1的电流密度充放电,2.0-4.8V电位范围内首次放电比容量高达260.0mAh·g-1,循环40次后放电比容量为244.7mAh·g-1,容量保持率为94.12%.  相似文献   

17.
The known aryne complex (PEt3)2Ni(eta2-C6H2-4,5-F2) (1a) reacts with a catalytic amount of Br2Ni(PEt3)2 over 1% Na/Hg to afford the dinuclear Ni(I) biarylyl complex [(PEt3)2Ni]2(mu-eta1:eta1-3,4-F2C6H2-3',4'-F2C6H2) (2a), which results from a combination of C-C bond formation and C-H bond rearrangement. The dinuclear benzyne [(PEt3)2Ni]2(mu-eta2:eta2-C6H2-4,5-F2) (3) was obtained by the reaction of 1a with a stoichiometric amount of Br2Ni(PEt3)2 over excess 1% Na/Hg, and 3 was found to catalyze the conversion of 1a to 2a. The reaction of 1a with B(C6F5)3 produced the trinuclear complex (PEt3)3Ni3(mu3:eta1:eta1:eta2-4,5-F2C6H2)(mu3:eta1:eta1:eta2-4,5-F2C6H2-4',5'-F2C6H2) (6). The addition of PEt3 to 6 produced 1 equiv of 1a and 1 equiv of [(PEt3)2Ni]2(mu-eta1:eta1-4,5-F2C6H2-4',5'-F2C6H2) (7a). Both 6 and 7a were identified as intermediates in the conversion of 1a to 2a. The analogue [(PEt3)(PMe3)Ni]2(mu-eta1:eta1-4,5-F2C6H2-4',5'-F2C6H2) (7b) was prepared by the addition of PMe3 to 6 and was structurally characterized. NMR spectroscopic evidence identified the additional asymmetric biarylyl [(PEt3)2Ni]2(mu-eta1:eta1-4,5-F2C6H2-3',4'-F2C6H2) (8a) during the conversion of 1a to 2a. The initial observation of 2 equiv of 8a for every equivalent of 2a produced from solutions of 7a suggests that 8a and 2a are formed from a common intermediate. A crossover labeling experiment shows that the C-H bond rearrangement steps in the conversion of 1a to 2a occur with the intermolecular scrambling of hydrogen and deuterium labels. The evidence collected suggests that Ni(I) complexes are capable of activating aromatic C-H bonds.  相似文献   

18.
Herein, the design, synthesis, optical properties, and mechanofluorochromism characteristics of a series of conjugates having covalently linked triarylborane (TAB) and anil/boranil units (TAB-anil: 1 a – 3 a and TAB-boranil: 1 – 3 ) are reported. The electronic interactions between TAB and anil/boranil in 1 a – 3 a and 1 – 3 were fine-tuned by changing the boryl moiety's position on the phenyl spacer connecting the BMes2 (Mes=mesityl) and anil/boranil units. A boryl moiety at the meta position ( 1 a ) of the phenyl spacer stabilizes the enolic form (E-OH), whereas a boryl moiety at the para position ( 2 a and 3 a ) stabilizes the keto form (Z-NH) in the solid state. However, in solution 1 a , 2 a , and 3 a exhibit keto–enol tautomerism in both ground and excited states. Compounds 1 a – 3 a and 1 – 3 show red-shifted absorption compared with 4 a and 4 , which are devoid of TAB moieties, which indicate effective participation of an empty p orbital on the boron center in 1 a – 3 a and 1 – 3 . Compounds 1 and 2 showed fluorescence variations in response to external stimuli such as mechanical grinding. Long phosphorescence lifetimes of 18–46 ms were observed for compounds 1 – 3 . The observed optical properties of 1 a – 3 a and 1 – 3 are rationalized in the context of quantum mechanical calculations.  相似文献   

19.
在DMF溶剂中,不外加催化剂使邻取代芳香醛(1)与5,5-二甲基-1,3-环己二酮(2)发生缩合和加成反应生成3,3,6,6-四甲基-4a-羟基-9-芳基-1,8-二氧代-2,3,4,4a,5,6,7,8,9,9a-十氢化-1H-氧杂蒽(3a-3d)。在同样条件下,邻羟基芳香醛与5,5-二甲基-1,3-环己二酮则发生缩合、加成和脱水反应生成3,3-二甲基-9-(5,5-二甲基-3-羟基-2-环己烯-1-酮-2-基)-1-氧代-2,3,4,9-四氢化-1-氧杂蒽(4a-4b)。用单晶X-射线分析法确定了产物3a和4a的晶体结构。  相似文献   

20.
以α-溴代苯乙酮为原料,在三乙胺作用下制备α-(1,2,4-三唑-1-基)-芳基乙酮(1a~1c),再与芳香醛发生羟醛缩合反应制备相应的含三唑基的查尔酮2a~2l,将中间体2a~2l同邻氨基硫酚合成新型的2,4-二芳基-3-(1,2,4-三唑-1-基)-2,3-二氢-1,5-苯并硫氮杂(3a~3l).所得化合物的结构经元素分析,IR,MS和1HNMR确认,同时用X射线衍射法测定了化合物2a和3a的晶体结构.  相似文献   

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