Bis(1,3-dithiol-2-ylidene)-[3.3]paracyclophanes: orthogonal intramolecular charge transfer interaction

A novel donor-cyclophane, orthogonally incorporated 1,3-dithiol-2-ylidene units (DT) to the cyclophane benzene rings, was synthesized in order to observe the intramolecular charge transfer (ICT) between the donor units and the cyclophane benzene rings.     

Preparation, properties, and catalytic activity of transition-metal complexes containing a ligated 2-methyl-3,3-diphenyl-1,3-diphosphapropene skeleton

2-Methyl-3,3-diphenyl-1-(2,4,6-tri-t-butylphenyl)-1,3-diphosphapropene behaved as an unsymmetrical chelating ligand for transition metal complexes and the 1,3-diphosphapropene moiety was hydrolyzed to afford the 1,3-diphosphapropan-1-ol derivative upon coordination. The palladium complex showed catalytic activity for the Sonogashira coupling reaction.     

Synthesis, properties and crystal structures of ferrocene derivatives containing pyrazinium and quinoxalinium units

The pyrazinium salt [FcCH₂pyz][BF₄] (1) and the quinoxalinium salt [FcCH₂quin][BF₄] (2) were prepared by the reaction of [FcCH₂][BF₄] with pyrazine and quinoxaline, respectively and characterised by spectroscopic methods, cyclic voltammetry and by single-crystal X-ray diffraction, which revealed the absence of any π-π-stacking motifs in the crystal structures.     

The interplay of inverted redox potentials and aromaticity in the oxidized states of new pi-electron donors: 9-(1,3-dithiol-2-ylidene)fluorene and 9-(1,3-dithiol-2-ylidene)thioxanthene derivatives

Derivatives of 9-(1,3-dithiol-2-ylidene)fluorene (9) and 9-(1,3-dithiol-2-ylidene)thioxanthene (10) have been synthesised using Horner-Wadsworth-Emmons reactions of (1,3-dithiol-2-yl)phosphonate reagents with fluorenone and thioxanthen-9-one. X-ray crystallography, solution electrochemistry, optical spectroscopy, spectroelectrochemistry and simultaneous electrochemistry and electron paramagnetic resonance (SEEPR), combined with theoretical calculations performed at the B3P86/6-31G** level, elucidate the interplay of the electronic and structural properties in these molecules. These compounds are strong two-electron donors, and the oxidation potentials depend on the electronic structure of the oxidised state. Two, single-electron oxidations (E(1)ox < E(1)ox) were observed for 9-(1,3-dithiol-2-ylidene)fluorene systems (9). In contrast, derivatives of 9-(1,3-dithiol-2-ylidene)thioxanthene (10) display the unusual phenomenon of inverted potentials (E(1)ox > E(1)ox) resulting in a single, two-electron oxidation process. The latter is due to the aromatic structure of the thioxanthenium cation (formed on the loss of a second electron), which stabilises the dication state (10(2+)) compared with the radical cation. This contrasts with the nonaromatic structure of the fluorenium cation of system 9. The two-electron oxidation wave in the thioxanthene derivatives is split into two separate one-electron waves in the corresponding sulfoxide and sulfone derivatives 27-29 owing to destabilisation of the dication state.     

Nitroketene dithioacetal chemistry. Part 2: Synthesis of novel 4-(alkylsulfanyl)-2-[1-nitromethylidene]-1,3-dithioles from the dipotassium salt of 2-nitro-1,1-ethylenedithiol

The reaction of the dipotassium salt of 2-nitro-1,1-ethylenedithiol with long chain alkyl halides in acetonitrile medium furnished the novel heterocyclic, 4-(alkylsulfanyl)-2-[1-nitromethylidene]-1,3-dithioles.     

Synthesis,Crystal Structure and Prosperities of 10-（4,5-Dibenzylthio- 1,3-dithiol-2-ylidene）anthracen-9（10H）-one

The title compound 10-（4,5-dibenzylthio-1,3-dithiol-2-ylidene）anthracen-9（10H）- one （C31H22OS4） has been synthesized, and its crystal structure was prepared by crystallization from CH2Cl2-MeOH. The crystal belongs to the triclinic system, space group Pi with a = 10.9758（3）, b = 11.4241（4）, c = 11.7460（2）A^°, α = 62.379（2）, β = 81.227（3）, γ = 80.321（2）°, Mr = 538.73, V = 1281.69（7） A^°^3, Z = 2, Dc = 1.396 g/cm^3, F（000） = 560,μ = 0.395 mm^-1, the final R = 0.0291 and wR = 0.0739. The molecular structure is severely distorted from planarity. The central ring of anthraquinone moiety adopts a boat conformation, while the two outer benzene rings are tilted in the opposite direction to form a dihedral angle of 23.65°. The photocurrent generation was measured and an anodic photocurrent response was obtained. The electronic spectrum was studied by using TDDFr method on the basis of optimized geometries with B3LYP method. The obtained results are in good agreement with the experimental values.     

Synthesis, structure and characterization of M---Sn (M=Mo, W) bonded heterobimetallic complexes containing bis(pyrazol-1-yl)methane ligands

The reaction of bis(pyrazol-1-yl)methane tetracarbonylmolybdenum(0) or tungsten(0) complexes with RSnCl₃ (R=Ph, Cl) at room temperature yielded heterobimetallic complexes CH₂(Pz)₂M(CO)₃(Cl)(SnCl₂R) (Pz represents substituted pyrazole; M=Mo or W; R=Ph or Cl) in good yields, which have been characterized by elemental analysis, ¹H NMR and IR spectroscopy. The reaction of bis(3,5-dimethyl-4-halopyrazol-1-yl)methane tetracarbonyl tungsten with PhSnCl₃ did not take place even in refluxing CH₂Cl₂. The electronic and steric characteristics of substituents on the pyrazole ring remarkably influence the structures of the products. The structures of CH₂(3,5-Me₂-4-BrPz)₂W(CO)₃(Cl)(SnCl₃) (8) and CH₂(4-BrPz)₂Mo(CO)₃(μ-Cl)(SnCl₂Ph) (17) (Pz: pyrazole) determined by X-ray crystallography show that no chlorine-bridged W---Sn bond is observed in complex 8, while one chlorine-bridged Mo---Sn bond exists in complex 17. The Sn---M bond length is 2.7438(5) Å in complex 8 (W---Sn) and 2.7559(4) Å in complex 17 (Mo---Sn).     

Synthesis,Crystal Structure,and Spectral Properties of a Novel Co(II) Complex Containing Imidazole Derivative

1 INTRODUCTION The metal-organic frameworks constructed from metals and π-conjugated ligands might have poten- tial applications in various fields, such as electronic, optical or magnetic materials[1～3]. Therefore, this kind of complex has attracted the increasing atten- tion of chemists, and considerable efforts have been devoted to the rational design and synthesis of new materials[4, 5]. Moreover, the organic-inorganic hybri- dized coordination complexes with imidazole deri- vatives …     

Synthesis and crystal structure of nickel(II) complexes with bis(5-methyl-2-thiophenemethyl)(2-pyridylmethyl)amine

A series of nickel(II) complexes having the (Me-Tp)₂PMA ligand ((Me-Tp)₂PMA = bis(5-methyl-2-thiophenemethyl)(2-pyridylmethyl)amine) with nitrates (1), chlorides (2), and perchlorates (3) as anions were synthesized and isolated. All these complexes were successfully characterized by physicochemical methods including X-ray crystallographic analysis. In complex 1, the ligand binds in a bidentate N₂ fashion, whereas in the cases of 2 and 3 the ligand binds in the tridentate N₂S form. The coordination geometry around the nickel(II) atoms in these complexes is distorted octahedral.     

Synthesis and molecular and crystal structure of 1-allyl-4-[2-cyano-2-(indan-1,3-dione-2-ylidene)ethylidene] -1, 4-dihydroquinoline

The reaction of 1-allyl-4-methylquinolinium bromide with 2-dicyanomethyleneindan-1,3-dione in the presence of a two-fold excess of triethylamine affords 1-allyl-4-[2-cyano-2-(indan-1,3-dione-2-ylidene) ethylidene]-1,4-dihydrogtiinoline, a representative of a new class of merocyanines. The structure of this compound has been established by X-ray structural analysis. A substantial intramolecular charge transfer and a hydrogen bond between the vinyl hydrogen atom and the indandione oxygen atom have been found.Dedeased in 1995Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 173–176, January, 1996.     

Synthesis,structure, and reactivity of sp carbon chains with bis(phosphine) pentafluorophenylplatinum endgroups: butadiynediyl (C4) through hexadecaoctaynediyl (C16) bridges,and beyond

The reaction of trans-[(C(6)F(5))(p-tol(3)P)(2)PtCl] (PtCl) and butadiyne (cat. CuI, HNEt(2)) gives trans-[(C(6)F(5))(p-tol(3)P)(2)Pt(Ctbond;C)(2)H] (PtC(4)H, 81 %), which reacts with excess HC(triple bond)CSiEt(3) under Hay coupling conditions (O(2), cat. CuCl/TMEDA, acetone) to yield PtC(6)Si (53 %). A solution of PtC(6)Si in acetone is treated with wet nBu(4)NF to generate PtC(6)H. The addition of ClSiMe(3) (F(-) scavenger) and then excess HC(triple bond)CSiEt(3) under Hay conditions gives PtC(8)Si (39 %). Hay homocouplings of PtC(4)H, PtC(6)H, and PtC(8)H (generated in situ analogously to PtC(6)H) yield PtC(8)Pt, PtC(12)Pt, and PtC(16)Pt (97-92 %). Reactions of PtC(4)H and PtC(6)H with PtCl (cat. CuCl, HNEt(2)) give PtC(4)Pt and PtC(6)Pt (69 %, 34 %). The attempted conversion of PtC(8)H to PtC(10)Si affords mainly PtC(16)Pt, with traces of PtC(20)Pt and PtC(24)Pt. The complexes PtC(x)Pt are exceedingly stable (dec pts 234 to 288 degrees C), and Et(3)P displaces p-tol(3)P to give the corresponding compounds Pt'C(8)Pt' and Pt'C(12)Pt' (94-90 %). The effect of carbon chain lengths upon IR nu(C(triple bond)C) patterns (progressively more bands), UV/Vis spectra (progressively red-shifted and more intense bands with epsilon >600 000 M(-1) cm(-1)), redox properties (progressively more difficult and less reversible oxidations), and NMR values are studied, and analyzed with respect to the polymeric sp carbon allotrope "carbyne". The crystal structure of PtC(12)Pt shows a dramatic, unprecedented degree of chain bending, whereas the chains in PtC(8)Pt, Pt'C(12)Pt', and PtC(16)Pt are nearly linear.     

新型2-(1,3-二噻烷-2-亚基)丙二酸Cd(Ⅱ)配合物的合成及晶体结构

合成了新型2-(1,3-二噻烷-2-亚基)丙二酸镉(Ⅱ)配合物[Cd(dyma)2(phen).H2O][dyma=2-(1,3-二噻烷-2-亚基)丙二酸,phen=1,10-菲啰啉],并通过元素分析和X-射线单晶衍射等手段对其进行了结构表征.结果表明:[Cd(dyma)2(phen).H2O]属于三斜晶系,空间群Pī;晶胞参数a=0.905 17(14)nm,b=1.221 94(19)nm,c=1.338 1(2)nm,α=69.761(2)°,β=72.313(2)°,γ=83.650(3)°,V=1.323 0(4)nm-3,Z=2,Dc=1.810 g.cm-3,μ=1.199 mm-1,F(000)=724,R1=0.037 5,wR2=0.085 7.中心Cd原子为七配位,分别与1,10-菲咯啉2个N原子、2个2-(1,3-二噻烷-2-亚基)丙二酸的羧基4个O原子和1个水分子配位.配位水分子与2个不同Cd(dyma)2(phen)分子中没有配位的羧基O原子形成分子间氢键,构筑成三维网状超分子配位聚合物.     

Preparation and characterization of 3-(4,5-ethylenedithio-1,3-dithiol-2-ylidene)naphthopyranone: a luminescent redox-active donor-acceptor compound

A new 1,3-dithiol-2-ylidene substituted naphthopyranone 2 has been synthesized and characterized. UV-vis spectroscopic and cyclic voltammetry results, interpreted on the basis of density functional theory, show that 2 displays an intramolecular charge-transfer transition and acts like a donor-acceptor (D-A) system. Furthermore, a weak fluorescence originating from the excited charge-transfer state is observed.     

3-(4,5-二苄硫基-1,3-二硫杂环戊烯-2-亚基)萘吡喃酮的合成、性质及量子化学计算

设计合成了一种新的具有D-π-A体系的有机分子:3-(4,5-二苄硫基-1,3-二硫杂环戊烯-2-亚基)萘吡喃酮,通过UV-vis,1H NMR,13C NMR,TOFMS和IR确定了其结构.初步研究了该化合物的电子光谱、荧光光谱和热稳定性.运用Gaussian 03量子化学程序包,采用密度泛函(DFT)B3PW91的方法优化了其基态几何结构,得到的几何参数与实验结果吻合得很好.研究结果表明,体系中存在着分子内的电荷转移,有较好的荧光性质,为寻找新的发光材料具有一定的实际意义.     

Syntheses,crystal structures,and DNA-binding properties of two nickel(II) complexes with 1,3-bis(benzimidazol-2-yl)-2-oxapropane derivatives

[Ni(obb)(DMF)₂(H₂O)]·(Pic)₂·0.5DMF (1) and [Ni(Etobb)₂]·(Pic)₂·2DMF (2) (obb = 1,3-bis(benzimidazol-2-yl)-2-oxapropane, Etobb = 1,3-bis(1-ethylbenzimidazol-2-yl)-2-oxapropane, Pic = picrate) have been synthesized and characterized by physicochemical and spectroscopic methods. The structures of both complexes have been determined by X-ray single-crystal diffraction. The coordination geometries of 1 and 2 can be described as distorted octahedra. The interaction of the nickel(II) complexes with calf thymus DNA was investigated by electronic absorption, fluorescence spectroscopy, and viscosity measurements. The experimental results suggest that 1 and 2 bind to DNA in an intercalation mode, and their binding affinity for DNA follows the order 1 > 2. DNA-binding behaviors can be attributed to the large coplanar aromatic rings in the V-shaped ligand and steric hindrance.     

Synthesis,structure, spectral properties,and electrochemistry of bis(crown ether) containing 1,3-distyrylbenzenes

The reaction of tetraethyl [1,3-phenylenedi(methylene)]bis(phosphonate) with formyl derivatives of benzocrown-ethers or formyl derivatives of o-dimethoxybenzene lead to high yield formation of the respectful bis(crown ether) containing 1,3-distyrylbenzenes or tetramethoxy-substituted 1,3-distyrenebenzenes. NMR spectra and quantum-chemical calculations showed the prevalence of unsymmetrical syn/anti,(syn,anti),syn/anti-conformations in 1,3-distyrylbenzenes. 1,3-Distyrylbenzenes absorb in shorter wavelength spectral region and have a weaker fluorescence than 1,4-distyrylbenzenes. The difficulty in the electrochemical reduction of 1,3-distyrylbenzenes comparing with 1,4-distyrylbenzenes is due to a less effective conjugation system in the metaderivatives.     

Synthesis and structure of novel 2-amino-l,3-dicyano-4-cyclopropyl-6-aryl-1,3-cyclohexadienes

The reaction of arylmethylenedicyanoacetates with 1,1-dicyano-2-cyclopropylpropene was studied and found to give 2-amino-1,3-dicyano-4-cyclopropyl-6-aryl-1,3-cyclohexadienes. The structure of 2-amino-6-(2-nitrophenyl)-1,3-dicyano-4-cyclopropyl-1,3-cyclohexadiene was corroborated by means of X-ray analysis.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 355–358, February, 1993.     

A novel π-donor–π-acceptor system: 1-(4,5-dimethyl-1,3-dithiol-2-ylidene)-1-ferrocenyl-3,3-dicyanopropene

The title compound was prepared by reacting the anion of malononitrile with the corresponding ethanal, and characterised by UV–vis absorption spectroscopy, cyclic voltammetry and X-ray crystallography. Attachment of an additional ferrocenyl donor group to the π-donor–π-acceptor system does not enhance intramolecular charge transfer, because its bulk distorts the planarity of the conjugated chain.     

二维配位聚合物[K2(5-nbdc)2Cd(Ⅱ)·imH·H2O]∞的合成和晶体结构(英)

The crystal structure of the title complex, [K₂(5-nbdc)₂Cd(Ⅱ)·imH·H₂O]_∞ (5-nbdc=5-nitro-1,3-benzenedicarbonate, imH=imidazole) has been determined by X-ray diffraction analysis. The crystal data are: tetragonal, space group P4₁, M_r=694.93 for CdC₁₉H₁₂N₄O₁₃K₂, a=1.018 6(10) nm, b=1.018 6(10) nm, c=2.436 7(5) nm; Z=4, V=2.528 2(6) nm³, F(000)=1 376, D_c=1.826 Mg·m^-3, μ=1.267 mm^-1. The title polymeric complex exhibits a two-dimensional framework, in which adjacent Cd(Ⅱ) ions are bridged by μ-O₄-5-nitro-1,3-benzenedicarbonate groups forming one-dimensional chains that are further linked by μ-O₃-5-nitro-1,3-benzenedicarbonate groups into two-dimensional anion rectangle sheets with large 32-membered rings. The strong π-π stacks of the benzene rings link these adjacent sheets into a three-dimensional van der Waals network. CCDC: 245527.