聚腈分子的飞秒时间分辨光克尔效应

本文利用飞秒时间分辩光克尔效应，对主链为Ｃ＝Ｎ结构的两种共轭聚腈高分子的溶液和薄膜进行研究，所测得的时间分辨光克尔信号均表现为超快响应。     

Coordination polymer chains built from CuII and adipate ions linked by hydrogen bonds to form a three‐dimensional framework structure

In the title compound, catena‐poly[bis[(2,2′‐bipyridine‐κ²N,N′)(1,1,3,3‐tetracyano‐2‐ethoxypropenido‐κN)copper(II)]‐μ₄‐hexanedioato‐κ⁶O¹,O^1′:O¹:O⁶,O^6′:O⁶], [Cu₂(C₉H₅N₄O)₂(C₆H₈O₄)(C₁₀H₈N₂)₂]_n, the adipate (hexanedioate) dianion lies across a centre of inversion in the space group P. The Cu^II centre adopts a distorted form of axially elongated (4+2) coordination, and the Cu^II and adipate components form a one‐dimensional coordination polymer from which the 2,2′‐bipyridine and 1,1,3,3‐tetracyano‐2‐ethoxypropenide components are pendent, and where each adipate dianion is bonded to four different Cu^II centres. The coordination polymer chains are linked into a three‐dimensional framework structure by a combination of C—H...N and C—H...O hydrogen bonds, augmented by a π–π stacking interaction.     

Multiple N—H...NC,C—H...NC and nitrile...π interactions in 4,4′‐bipyridine‐1,1′‐diium bis(1,1,3,3‐tetracyano‐2‐ethoxypropenide): structure determination and DFT calculations of anion...π cation interaction energies

Polynitrile anions are important in both coordination chemistry and molecular materials chemistry, and are interesting for their extensive electronic delocalization. The title compound crystallizes with two symmetry‐independent half 4,4′‐bipyridine‐1,1′‐diium (bpyH₂²⁺) cations and two symmetry‐independent 1,1,3,3‐tetracyano‐2‐ethoxypropenide (tcnoet⁻) anions in the asymmetric unit. One of the bpyH₂²⁺ ions is located on a crystallographic twofold rotation axis (canted pyridine rings) and the other is located on a crystallographic inversion center (coplanar pyridine rings). The ethyl group of one of the tcnoet⁻ anions is disordered over two sites with equal populations. The extended structure exhibits two separate N—H...NC hydrogen‐bonding motifs, which result in a sheet structure parallel to (010), and weak C—H...NC hydrogen bonds form joined rings. Two types of multicenter CN...π interactions are observed between the bpyH₂²⁺ rings and tcnoet⁻ anions. An additonal CN...π interaction between adjacent tcnoet⁻ anions is observed. Using density functional theory, the calculated attractive energy between cation and anion pairs in the tcnoet⁻...π(bipyridinediium) interactions were found to be 557 and 612 kJ mol⁻¹ for coplanar and canted bpyH₂²⁺ cations, respectively.     

Three zinc(II) and cadmium(II) complexes containing 4‐amino‐3,5‐bis(pyridin‐2‐yl)‐1,2,4‐triazole and polynitrile ligands: synthesis,molecular and supramolecular structures,and photoluminescence properties

Three photoluminescent complexes containing either Zn^II or Cd^II have been synthesized and their structures determined. Bis[4‐amino‐3,5‐bis(pyridin‐2‐yl)‐1,2,4‐triazole‐κ²N ¹,N ⁵]bis(dicyanamido‐κN ¹)zinc(II), [Zn(C₁₂H₁₀N₆)₂(C₂N₃)₂], (I), bis[4‐amino‐3,5‐bis(pyridin‐2‐yl)‐1,2,4‐triazole‐κ²N ¹,N ⁵]bis(dicyanamido‐κN ¹)cadmium(II), [Cd(C₁₂H₁₀N₆)₂(C₂N₃)₂], (II), and bis[4‐amino‐3,5‐bis(pyridin‐2‐yl)‐1,2,4‐triazole‐κ²N ¹,N ⁵]bis(tricyanomethanido‐κN ¹)cadmium(II), [Cd(C₁₂H₁₀N₆)₂(C₄N₃)₂], (III), all crystallize in the space group P , with the metal centres lying on centres of inversion, but neither analogues (I) and (II) nor Cd^II complexes (II) and (III) are isomorphous. A combination of N—H…N and C—H…N hydrogen bonds and π–π stacking interactions generates three‐dimensional framework structures in (I) and (II), and a sheet structure in (III). The photoluminescence spectra of (I)–(III) indicate that the energies of the π–π* transitions in the coordinated triazole ligand are modified by minor changes of the ligand geometry associated with coordination to the metal centres.     

Poly[[chlorido(1,10‐phenanthroline‐κ2N,N′)copper(II)]‐μ3‐1,1,3,3‐tetracyano‐2‐ethoxypropenido‐κ3N:N′:N′′]: coordination polymer sheets linked into bilayers by hydrogen bonds

In the title compound, [Cu(C₉H₅N₄O)Cl(C₁₂H₈N₂)]_n or [Cu(tcnoet)Cl(phen)]_n, where phen is 1,10‐phenanthroline and tcnoet is 1,1,3,3‐tetracyano‐2‐ethoxypropenide, the axially elongated (4 + 2) coordination polyhedron around the Cu^II centre contains N atoms from three different tcnoet ligands. The resulting coordination polymer takes the form of sheets which are linked in pairs by a single C—H...N hydrogen bond to form bilayers. The bond lengths provide evidence for significant bond fixation in the phen ligand and extensive electronic delocalization in the tcnoet ligand, where the two –C(CN)₂ units are rotated, in conrotatory fashion, out of the plane of the central C₃O fragment.     

1,1′‐Diethyl‐4,4′‐bipyridine‐1,1′‐diium bis(1,1,3,3‐tetracyano‐2‐ethoxypropenide): multiple C—H...N hydrogen bonds form a complex sheet structure

In the title salt, C₁₄H₁₈N₂²⁺·2C₉H₅N₄O⁻, the 1,1′‐diethyl‐4,4′‐bipyridine‐1,1′‐diium dication lies across a centre of inversion in the space group P2₁/c. In the 1,1,3,3‐tetracyano‐2‐ethoxypropenide anion, the two independent –C(CN)₂ units are rotated, in conrotatory fashion, out of the plane of the central propenide unit, making dihedral angles with the central unit of 16.0 (2) and 23.0 (2)°. The ionic components are linked by C—H...N hydrogen bonds to form a complex sheet structure, within which each cation acts as a sixfold donor of hydrogen bonds and each anion acts as a threefold acceptor of hydrogen bonds.     

Tris(2,2′‐bipyridine)iron(II) bis(1,1,3,3‐tetracyano‐2‐ethoxypropenide) dihydrate: chiral hydrogen‐bonded frameworks interpenetrate in three dimensions

In the title compound, [Fe(C₁₀H₈N₂)₃](C₉H₅N₄O)₂·2H₂O, the chiral cations lie across twofold rotation axes in the space group C2/c. The anions and the water molecules are linked by two independent O—H...N hydrogen bonds to form C₂²(8) chains, and these chains are linked by the cations via C—H...N and C—H...O hydrogen bonds to form two interpenetrating three‐dimensional frameworks, each of which contains only one enantiomeric form of the chiral cation.     

Synthesis and Crystal Structure of a Three-dimensional Coordination Polymer {[Cd(cda)2]·2CH3OH}n Generated from Cadmium(Ⅱ) and Carbamyldicyanomethanide Anion Bridging Ligand

The three-dimensional coordination polymer {[Cd(cda)2](2CH3OH}n has been syn- thesized by Na(cda) (cda = carbamyldicyanomethanide anion) and hydrated cadmium perchlorate in methanol solution. The crystal belongs to monoclinic, space group C2/c with a = 15.686(3), b = 8.1650(18), c = 13.119(3) (A), β= 119.334(2)°, V = 1464.8(6) (A)3, Z = 4, C10H12CdN6O4, Mr = 392.66, Dc = 1.780 g/cm3, F(000) = 776 and μ = 1.516 mm-1. The structure was refined to R = 0.0248 and wR = 0.0628 for 1176 observed reflections (I ＞ 2σ(I)). The Cd(II) ion is coordinated by two amide- oxygen and four nitrile-nitrogen atoms from six different cda bridging ligands, forming a three- dimensional structure.     

Synthesis and Crystal Structure of a Three-dimensional Coordination Polymer {[Cd(cda)_2]·2CH_3OH}_n Generated from Cadmium(II) and Carbamyldicyanomethanide Anion Bridging Ligand

1 INTRODUCTION The polynitrile-ligands, such as TCNE, TCNB, TCNQ, TCNP, tcm, dca and so on, are of ideal multi-functional bridging ligands. Many complexes with poly-nitriles as bridging ligands and uncoor- dinated ligand (electron acceptors) display dist…