对称双吡咯甲烷的合成与分子内氢键的研究

５－甲基吡咯－２－羧酸酯在磺酰氢，溴或四乙酸铅作用下，生成相应的在５－甲基上含取代基的产物，后者不经分离不便可自缩合得标题化合物，核磁共振氢谱研究和分子构象木匠，当３，３位的取代基为甲酸（酯）基或乙酸（酯）基时，可形成３，３位酯基与另一吡咯环上的氮氢之间的分子内氢键，而３，３位是其它取代基，如乙酰基，丙酸（酯）基，丁酸（酯）基时不能形成类似的分子内氢键。     

巨型给-受体分子开关化合物的合成及性质研究

以构象可变的间苯二酚杯[4]芳烃孔穴化合物(Cavitand)为分子开关母体, 合成了一种新颖的给-受体(D-A)型分子开关化合物(化合物1), 该分子是目前已知分子量最大的D-A型间苯二酚杯[4]芳烃Cavitand (分子量为3064.9966). 其中, 以卟啉为给体, 富勒烯为受体. 在pH诱导下, 化合物1可发生构象变化, 即由原来的关闭状(vase)转为打开状(kite); 而在降低温度和引入Zn²⁺的条件下, 不能促使化合物1发生构象变化. pH诱导构象发生变化的原因, 是酸的加入会导致喹喔啉手臂上的N原子发生质子化, 从而使得形成的静电排斥作用促使手臂之间相互远离. 此外, 对化合物1的光物理性质研究表明, 存在卟啉向富勒烯的单线态能量转移, 其单线态能量转移速率常数为1.1×10⁷ s^-1, 单线态能量转移效率为9.63%.     

分子内电荷转移化合物的合成

以对硝基甲苯和苯酚为原料,经重氮化和偶合反应合成了新的具有分子内电荷转移能力的偶氮化合物(1),其结构经UV,1H NMR和元素分析表征.     

Synthesis, Characterization, and Theoretical Study of Sulfur-Containing Donor-Acceptor DCNQI Derivatives with Photoinduced Intramolecular Electron Transfer

The donor-acceptor compounds N,N'-dicyanobenzo[b]naphtho[2,3-e][1,4]dithiin-6,11-quinonediimine (9a) and N,N'-dicyanobenzo[b]naphtho[2,3-e][1,4]oxathiin-6,11-quinonediimine (10a) and their methyl-substituted derivatives (9b and 10b-d, respectively) have been prepared, and their structural and electronic properties have been characterized by both experimental techniques and quantum-chemical calculations. The (1)H-NMR spectra evidence the existence of a syn/anti isomerism in solution. Both experimental and theoretical data suggest that the preferred configuration of the N-CN groups corresponds to a syn isomer for 9 and to an anti isomer for 10. The X-ray analysis performed for 9b reveals that molecules are not planar and pack in vertical stacks showing an overlap between donor and acceptor moieties of adjacent molecules. In agreement with X-ray data, theoretical calculations predict that both for 9 and 10 the acceptor DCNQI moiety is folded and adopts a butterfly-type structure and the donor moiety is bent along the line passing through the heteroatoms. The energy difference between planar and butterfly structures is calculated to be < 3 kcal/mol at the ab initio 6-31G level. The UV-vis spectra present a broad absorption in the visible which corresponds to a photoinduced intramolecular electron transfer from the high-energy HOMO furnished by the donor moiety to the low-energy LUMO located on the DCNQI fragment. Cyclic voltammetry displays one oxidation peak to the cation and two one-electron reduction waves to the anion and dianion. Theoretical calculations show the planarization of the acceptor/donor moiety induced by reduction/oxidation. The formation of stable radical anions is corroborated by the intense EPR signals recorded for reduced 9. The assignment of the hyperfine coupling constants of the EPR spectra is consistent with the existence of a preferred syn configuration.     

The Synthesis of Strained Methylene-bridged Bicyclic Olefins by the Intramolecular Wittig Reaction

A convenient synthesis of the strained methylene-bridged trans-cyclooctenes bicyclo[3.3.1]-1 (2)-nonene (1) , bicyclo[4.2.1]-1(8)-nonene (2) , and bicyclo[4.2.1]-1(2)-nonene (3) by the intramolecular Wittig reaction is described (see Schemes 1–4). The (3-oxocycloalkyl)alkyl-phosphonium bromides 20 , 27 and 38 undergoing cyclization to the bridgehead olefins are formed by simple reaction sequences. The spectral properties (IR., ¹H-NMR., ¹³C-NMR., and UV.) of the olefins are discussed with regard to their strain.     

Synthesis,Bonding and Reactivity of a Terminal Titanium Alkylidene Hydrazido Compound

We report a detailed study of the reactions of the Ti?NNCPh₂ alkylidene hydrazide functional group in [Cp*Ti{MeC(NiPr)₂}(NNCPh₂)] ( 8 ) with a variety of unsaturated and saturated substrates. Compound 8 was prepared from [Cp*Ti{MeC(NiPr)₂}(NtBu)] and Ph₂CNNH₂. DFT calculations were used to determine the nature of the bonding for the Ti?NNCPh₂ moiety in 8 and in the previously reported [Cp₂Ti(NNCPh₂)(PMe₃)]. Reaction of 8 with CO₂ gave dimeric [(Cp*Ti{MeC(NiPr)₂}{μ‐OC(NNCPh₂)O})₂] and the “double‐insertion” dicarboxylate species [Cp*Ti‐{MeC(NiPr)₂}{OC(O)N(NCPh₂)C(O)O}] through an initial [2+2] cycloaddition product [Cp*Ti{MeC(NiPr)₂}{N(NCPh₂)C(O)O}], the congener of which could be isolated in the corresponding reaction with CS₂. The reaction with isocyanates or isothiocyanates tBuNCO or ArNCE (Ar=Tol or 2,6‐C₆H₃iPr₂; E=O, S) gave either complete NNCPh₂ transfer, [2+2] cycloaddition to Ti?N_α or single‐ or double‐substrate insertion into the Ti?N_α bond. The treatment of 8 with isonitriles RNC (R=tBu or Xyl) formed σ‐adducts [Cp*Ti{MeC(NiPr)₂}(NNCPh₂)(CNR)]. With Ar^F5CCH (Ar^F5=C₆F₅) the [2+2] cycloaddition product [Cp*Ti{MeC(NiPr)₂}{N(NCPh₂)C(Ar^F5)C(H)}] was formed, whereas with benzonitriles ArCN (Ar=Ph or Ar^F5) two equivalents of substrate were coupled in a head‐to‐tail manner across the Ti?N_α bond to form [Cp*Ti{MeC(NiPr)₂}{N(NCPh₂)C(Ar)NC(Ar)N}]. Treatment of 8 with RSiH₃ (R=aryl or Bu) or Ph₂SiH₂ gave [Cp*Ti{MeC(NiPr)₂}{N(SiHRR′)N(CHPh₂)}] (R′=H or Ph) through net 1,3‐addition of Si? H to the N? N?CPh₂ linkage of 8 , whereas reaction with PhSiH₂X (X=Cl, Br) led to the Ti?N_α 1,2‐addition products [Cp*Ti{MeC(NiPr)₂}(X){N(NCPh₂)SiH₂Ph}].     

Synthesis and Crystal Structure of a New Class of Oxygen Bridged Bicyclic Tetraphosphazanes

Abstract

The reaction of primary amine hydrochlorides with phosphorus oxychloride in the presence of 1/4 mole of H₂0 yields the title compounds I (R = C₆H₅-, 4-CH₃CH₆H₄ ^?′ 4-CH₃CH₆H₄ ^?, 3-CH₃CH₆H₄ ^? CF₃CH₂-). Hydrochlorides Of more basic amines do not yield any cyclic material. The compound I (R = C₆H₅) was isolated as one isomer. An X-ray crystallographic study has shown an open ring structure in which the two chlorine atoms are positioned on the same face of the P₄N₄ ring as the P-O-P bridge.     

Synthesis and Crystal Structure of a Genistein-derived Compound

A genistein derivative, 5-hydroxy-3-（4-hydroxyphenyl）-7-（2-（piperidin- 1-yl）ethoxy）- 4H-chromen-4-one 3, was designed, prepared and structurally characterized by single-crystal X-ray diffraction. X-ray structure analysis reveals that 3 crystallizes in the orthorhombic system, space group Pbca, with a = 16.238（3）, b = 10.308（2）, c = 22.987（5）A, V = 3847.6（13）A3, Z = 8,μ= 0.093 mm^-1, Dc = 1.317 g/cm^3, F（000） = 1616, R = 0.0789 and wR = 0.1554 for 1463 observed reflections with I 〉 2σ（I）.     

Synthesis and Structure of A Novel Caged Bicyclic Phosphate Flame Retardant

IntroductionThe ecological safety of polymer flame retardant has become a major subject in the modern polymer industry, and there is an international demand for the control of polymer flammability without the use of halogenated additives. Consequently, current research is mainly focused on looking for environmental friendly additives in the form of organophosphorus compounds, which are being thought as the alternatives of the halogen containing flame retardants1. Among the organophosphorus fla…     

氢键和供体－受体相互作用驱动的酰肼异体二聚体组装

A new series of hydrogen bonding-driven heterodimers have been self-assembled in chloroform from hydrazide-based monomers. Additional intermolecular donor-acceptor interaction between the electron-rich bis（p-phenylene）-34-crown-10 unit and the electron-deficient naphthalene diimide unit has been utilized to increase the stability of the dimmers, and pronounced cooperativity of the two discrete non-covalent forces to stabilize the dimer has been revealed by the quantitative ^1H （2D） NMR and UV-Vis experiments.     

Synthesis,Crystal Structure and Fluorescence of a Bicyclic Product Containing Chromene and Propargylamine Skeleton

The bicyclic product containing a chromene skeleton and a propargylamine skeleton(C_(22)H_(22)N_2O_2) was synthesized from the double sites of terminal alkyne, piperazine derivative and formaldehyde via one-pot procedure. Its structure was characterized by ~1H NMR, ~(13)C NMR, IR and H RMS, and further confirmed by single-crystal X-ray diffraction. It crystallizes in the monoclinic system, space group P21/n with a = 12.6571(14), b = 11.3249(12), c = 12.6571(14) ?, β = 105.22°,V = 1750.6(3) ?~3, Z = 4, R = 0.0568 and w R = 0.1444. The fluorescence of the product was discussed.     

吩噻嗪衍生物的分子内电荷转移激发态的特性

A series of N-bonded donor-acceptor derivatives of phenothiazine containing benzene (PHPZ), anisole (ANPZ), pyridine (PYPZ), naphthalene (NAPZ), acetophenone (PEPZ), and benzonitrile (BNPZ) as an electron acceptor was synthesized. Their photophysical properties were investigated in solvents of different polarities by absorption and emission techniques. These studies clearly reveals the existence of an intramolecular charge transfer (ICT) excited state in the latter four compounds. The solvent dependent Stokes shift values were analyzed by the modified Lippert-Mataga equation to obtain the excited state dipole moment values. The large excited state dipole moment suggests that the full electron transfer takes place in the A-D systems. The obtained values of redox potentials indicate that both subunits of all the A-D molecules studied interact very weakly in the ground states. The results obtained from the analysis of the CT fluorescence spectra confirm that the small conformational changes accompanying excited state charge transfer, the twist angle between the donor and acceptor moieties in the excited 1CT state seems to be similar to that in the ground state.     

Synthesis and Crystal Structure of a New Mn8 Compound with Tripodal Ligand

A new manganese compound [Mn8(tmp)2(Htmp)4((CH3)3CCO2)4(py)2Cl2]·2py (1·2py, H3tmp = 1,1,1-tri(hydroxymethyl)propane, py = pyramid) has been synthesized and its structure was characterized by IR, elemental analysis and X-ray diffraction. Compound 1 belongs to the triclinic system, space group P1 with a = 13.378(5), b = 14.334(5), c = 15.012(6) , α = 107.637(5), β = 95.635(3), γ = 92.825(4)°, V = 2720.7(17) 3, Z = 1, C76H124N4O26Cl2Mn8, Mr = 2022.23, Dc = 1.234 Mg/m3, μ = 1.007 mm-1, F(000) = 1052, T = 293(2) K, the final R = 0.0755 and wR = 0.2163 for all 6463 observed reflections (I > 2σ(I)). X-ray analysis shows that the core of 1 contains a [Mn8] mixed-valence rod-like unit consisting of six edge-sharing triangles (Mn3), each of which is bridged by a μ3-oxygen atom.     

由喹喔啉类配体构筑的钴的配合物的水热合成及晶体结构

采用水热法合成了一个配合物[Co(AIP)(HAIP)2].(OH)2(HAIP=2-(9-anthryl)-1H-imidazo[4,5-f][1,10]phenanthroline)1,并对其进行了元素分析、红外光谱、热重表征和X射线单晶衍射测定。配合物1属于单斜晶系,空间群为C2/c,晶胞参数为:a=1.152 9(2),b=3.673 6(7),c=1.584 1(3)nm,α=107.73(3)°,V=6.382(2)nm3,Z=4(291(2)K)。在晶体中,中心离子Co(Ⅲ)分别与来自于2个不同的HAIP配体和1个AIP配体上的6个氮原子形成六配位的变形八面体构型。     

由喹喔啉类配体构筑的钴的配合物的水热合成及晶体结构

采用水热法合成了一个配合物[Co(AIP)(HAIP)₂]·(OH)₂(HAIP=2-(9-anthryl)-1H-imidazo[4,5-f][1,10] phenanthroline)1, 并对其进行了元素分析、红外光谱、热重表征和X射线单晶衍射测定。配合物1属于单斜晶系, 空间群为C2/c, 晶胞参数为:a=1.152 9(2), b=3.673 6(7), c=1.584 1(3) nm, α=107.73(3)°, V=6.382(2) nm³, Z=4(291(2) K)。在晶体中, 中心离子Co(Ⅲ)分别与来自于2个不同的HAIP配体和1个AIP 配体上的6个氮原子形成六配位的变形八面体构型。     

Synthesis and Crystal Structure of a New Glycinato Copper Compound

1 INTRODUCTION Amino acids (AA) are some of the most important biological ligands, and metal ions are known to par- ticipate in a variety of biological reactions, therefore, research on the coordination behavior of metal-ami- no acid complexes is one of the most essential ele- ments of chemical biology[1, 2]. For over three deca- des their structures have been of considerable inte- rest and importance in coordination chemistry[2, 3]. Studies of these relatively simple complexes may en- ha…     

一种含P-N键的双环磷酸酯化合物的合成及晶体结构

合成了 1种双环磷酸酯 磷酰胺类阻燃剂——— 1 ,2 二 (2 氧代 5,5 二甲基 1 ,3,2 二氧磷杂环己 2 氨基 )乙烷 [BPEA](C1 2 H2 6N2 O6P2 ,Mr=356.2 9) ,用X 射线衍射法、红外光谱和1 HNMR表征了该化合物。晶体学数据为 :单斜晶系 ,空间群P2 1 /n ,a =6.9657(1 0 ) ,b =1 4 571 (3) ,c =8.642 6(1 2 ) ;β =91 .1 91 (1 1 )°;V =877.0 (2 ) 3,Z =2 ,Dc=1 .349g/cm3,μ =0 .2 76mm- 1 ,F(0 0 0 ) =380。结构由直接法解出 ,用全矩阵最小二乘法修正 ,最终偏离因子R =0 .0 4 0 5,wR =0 0 890 (I >2σ(I) )的可观测衍射 1 354个。BPEA的晶体结构表明 ,它是通过乙二胺联系的 2个六员环构成并以对称中心分布。     

Enantioselective Formation of Bicyclic Lactones by Rhodium-Catalyzed Intramolecular CH-insertion reactions

The decomposition of cyclohexyl diazoacetate ( 5a ) in the presence of the chiral [Rh₂{(2S)-mepy}₄] catalyst leads to a 3:1 cis/trans mixture of bicyclic lactone 6a with an enantiomeric excess of 95–97% (cis) and 90% (trans). The conformationally rigid tert-butyl derivatives 5b and 5c afford, in the presence of the same catalyst, 6b and 6c , respectively, via insertion into the equatorial C? H bonds exclusively, with ee's of ca. 95%. A remarkable degree of induction (92–95%) results in the lactone 6g upon decomposition of 1-isopropyl-2-methylpropyl diazoacetate ( 5g ). The diazoacetates derived from 1-methylcyclohexanol, cyclopentanol and 1-methylcyclopentanol ( 5d–f ) afford under similar conditions insertion products with higher diastereoselectivity, but significantly lower enantioselectivity. Other dirhodium catalysts are less efficient.