Highly functionalized dimeric tetraethynylethenes and expanded radialenes: strong evidence for macrocyclic cross-conjugation

A selection of dimeric tetraethynylethenes (TEEs) and perethynylated expanded radialenes, containing different donor/acceptor substitution patterns, have been prepared and fully characterized. The first X-ray crystal structure of an expanded [6]radialene, with twelve peripheral 3,5-di(tert-butyl)phenyl substituents, is presented. This macrocycle, the all-carbon core of which is isomeric with fullerene C60, adopts a non-planar, "chair-like" conformation. Also a TEE dimer, carrying N,N-dimethylaniline donor substituents, has been subjected to an X-ray crystallographic analysis. The electronic properties were studied by UV/Vis spectroscopy and electrochemistry, providing fundamental insight into mechanisms of pi-electron delocalization in the acyclic and macrocyclic chromophores. Donor or donor-acceptor-substituted dimeric TEE derivatives show very strong absorptions extending over the entire UV/Vis region; their longest wavelength absorption bands have high charge-transfer character. Macrocyclic cross-conjugation in the expanded radialenes becomes increasingly efficient with increasing donor-acceptor polarization. A dual, strongly solvent-polarity-dependent fluorescence was observed for a tetrakis(N,N-dimethylaniline)-substituted dimeric TEE; this interesting emission behavior is explained by the twisted intramolecular charge-transfer (TICT) state model. Donor-substituted expanded radialenes display huge resonance-enhanced third-order nonlinear optical coefficients.     

Aromaticity and electron affinity of Carbo(k)-[3]radialenes, k=0, 1, 2

Aromaticity enhancement is a possible driving force for the low reduction potentials of buta-1,3-diynediyl-expanded [N]radialenes: this hypothesis is theoretically analyzed for the expanded [3]radialene prototype. This study is undertaken within a more general prospect, namely the evaluation of the variation of aromaticity with endocyclic and peripheral carbomeric expansion of [3]radialene and its mono- and dianions. The structures, denoted as [C-H](6) (h)[C-C](3) (k)carbo-[3]radialene(q) (h=0, 1; k=0, 1, 2; q=0, -1, -2), were optimized in relevant singlet, doublet, or triplet spin states at the B3PW91/6-31G** level. They were found to be all planar. The structural aromaticity was measured through the average bond length d(av) over the [C-C](3) (k)carbo-[3]radialene core, and by the corresponding bond-length equalization parameter sigma(d), related to Krygowski's GEO. The magnetic aromaticity was measured by Schleyer's NICS values at the center of the rings. Regarding the relative variation of NICS and sigma(d), two classes of species can be distinguished according to their endocyclic expansion level. The species with a nonexpanded (k=0) or doubly expanded (k=2) ring constitute the first class: they exhibit D(3h) symmetry and a strong correlation of NICS with sigma(d). The species with a singly expanded ring (k=1) fall far from the correlation line, and constitute the second class. This class distinction is related to the degeneracy scheme of the frontier orbitals of the neutral representative. A finer appraisal of the electron (de)localization is brought by the ELF (Electron Localization Function) analysis of the electron density. It allows for a weighting of relevant resonance forms. Unsubstituted species are well described by the superimposition of two or three resonance forms. For (doublet spin state) monoanionic species, their respective weights are validated by comparison with AIM spin density. The weighted mean, n, of the formal numbers of paired pi(z) electrons in the resonance forms was calculated and compared with the closest even integer of either forms 4m+2 or 4m. A density-based continuous generalization of the orbital-based discrete Hückel rule is then heuristically proposed through an analytical correlation of NICS versus sigma(d), n, and S, the spin of the species. The frontier-orbital-degeneracy pattern of neutral species is discussed with respect to structural and magnetic aromaticity criteria. A decreasing HOMO-LUMO gap versus endocyclic expansion is obtained, but [C-C](3) (1)carbo-[3]radialene possesses the highest HOMO and LUMO energies. Vertical and adiabatic electron affinities of neutral and monoanionic species were also computed and compared with related experimental data.     

Hexaaryl[3]radialenes

Reactions of diarylmethyl anions whose conjugate acids are more acidic than diphenylmethane with tetrachlorocyclopropene are found to afford hexaaryl-[3]radialenes in modest to good yields, thus leading to the first synthesis of hexaphenyl[3]radialene itself too; X-ray crystalographic analysis of hexakis(p-cyanophenyl)[3]radialene reveals a double three-bladed conformation.     

Expanded radialenes with bicyclo[4.3.1]decatriene units: new precursors to cyclo[n]carbons

A new method for the formation of conjugated polyynes has been developed based on both the rearrangement of vinylidenes to alkynes and the [2+1] cheletropic fragmentation of dialkynylmethylenebicyclo[4.3.1]deca-1,3,5-triene derivatives. A model study of the photolysis of simple dialkynylmethylenebicyclo[4.3.1]deca-1,3,5-trienes resulted in cheletropic fragmentation followed by 1,2-migration to give the corresponding linear polyynes, although undesired isomerization to methylenebicyclo[5.3.0]triene derivatives took place concurrently. Expanded [3]-, [4]-, [5]-, and [6]radialene derivatives with exocyclic bicyclo[4.3.1]decatriene units were prepared by oxidative coupling of the monomeric units as precursors to the corresponding cyclo[n]carbons, monocyclic forms of carbon clusters. The spectroscopic properties of the expanded radialenes were investigated in connection with cross conjugation of the core pi system and with its perturbation by the extraannular bicyclic pi system. In negative-mode laser-desorption time-of-flight (LD-TOF) mass spectra, the expanded radialenes exhibited peaks due to the corresponding cyclo[n]carbon anions (n = 18, 24, 30, and 36) formed by the stepwise loss of the aromatic indane fragments.     

Radical Cations of Dithia- and Tetraselenaradialenes with Restricted Delocalization of the Unpaired Electron

The radical cations of the permethylated dithia[6]radialene 1 and the tetraselena[8]radialene 2 have been investigated by ESR- and ENDOR-spectroscopy. It is shown that in the radical cation of 1 the unpaired electron is delocalized only in one half of the molecule. The magnitude of the (33)S coupling constant suggests a restricted localization within the 2,3-dithiatetramethyl-butadiene unit. We ascribe the slow electron transfer from one part of the molecule to the other to steric effects. The analysis of the ESR spectrum of 2(*)()(+)() shows that only two of the four selenium atoms are involved. The delocalization of the unpaired electron is restricted to only one of the divinyl diselenide moieties with a slow electron transfer rate to the other one.     

Superstructure-dependent optical and electrical properties of an unusual face-to-face, pi-stacked, one-dimensional assembly of dehydrobenzo[12]annulene in the crystalline state

To develop a novel pi-conjugated molecule-based supramolecular assembly, we designed and synthesized trisdehydrotribenzo[12]annulene ([12]DBA) derivative 2 with three carboxyl groups at the periphery. Recrystallization of 2 from DMSO gave a crystal of the solvate 23 DMSO. Crystallographic analysis revealed, to our surprise, that a face-to-face pi-stacked one-dimensional (1D) assembly of 2 was achieved and that the DMSO molecule played a significant role as a "structure-dominant element" in the crystal. This is the first example of [12]DBA to stack completely orthogonal to the columnar axis. To reveal its superstructure-dependent optical and electrical properties, 2 and its parent molecule 1, which crystallizes in a herringbone fashion, were subjected to fluorescence spectroscopic analysis and charge-carrier mobility measurements in crystalline states. The 1D stacked structure of 2 provides a red-shifted, broadened, weakened fluorescence profile (lambda(max) = 545 nm, phi(F) = 0.01), compared to 1 (lambda(max) = 491 nm, phi(F) = 0.12), due to strong interactions between the p orbitals of the stacked molecules. The charge-carrier mobility of the single crystal of 23 DMSO, as well as 1, was determined by flash photolysis time-resolved microwave conductivity (FP-TRMC) measurements. The single crystal of 23 DMSO revealed significantly-anisotropic charge mobility (sigma(mu) = 1.5x10(-1) cm(2) V(-1) s(-1)) along the columnar axis (crystallographic c axis). This value is 12 times larger than that along the orthogonal axis (the a axis).     

meso-Trifluoromethyl-substituted expanded porphyrins

A series of meso-trifluoromethyl-substituted expanded porphyrins, including N-fused [24]pentaphyrin 3, [28]hexaphyrin 4, [32]heptaphyrin 5, [46]decaphyrin 6, and [56]dodecaphyrin 7, were synthesized by means of an acid-catalyzed one-pot condensation reaction of 2-(2,2,2-trifluoro-1-hydroxyethyl)pyrrole (1) as the first examples bearing meso-alkyl substituents. Besides these products, porphyrin 2 and two calix[5]phyrins 8 and 9 were also obtained. [28]Hexaphyrin 4 was quantitatively oxidized to [26]hexaphyrin 14 with MnO(2). These expanded porphyrins have been characterized by mass spectrometry, (1)H and (19)F NMR spectroscopy, and UV/Vis spectroscopy. The single-crystal structures have been determined for 3, 4, 6, 7, and 14. The N-fused [24]pentaphyrin 3 displays a distorted structure containing a tricyclic fused moiety that is similar to those of meso-aryl-substituted counterparts, whereas 8 and 9 are indicated to take roughly planar conformations with an inverted pyrrole opposite to the sp(3)-hybridized meso-carbon atom. Both [28]- and [26]hexaphyrins 4 and 14 have figure-of-eight structures. Solid-state structures of the decaphyrin 6 and dodecaphyrin 7 are remarkable, exhibiting a crescent conformation and an intramolecular two-pitch helical conformation, respectively.     

Macrocyclic Tetraethynylethene Molecular Scaffolding: Perethynylated aromatic dodecadehydro[18]annulenes,antiaromatic octadehydro[12]annulenes,and expanded radialenes

Tetraethynylethene (3,4-diethynylhex-3-ene-1,5-diyne) molecular scaffolding provided access to novel macrocyclic nanometer-sized C-rich molecules with unusual structural and electronic properties. Starting from cis-bis-deprotected cis-bis(trialkylsilyl)protected tetraethynylethenes, the per(silylethynyl)ated octadehydro[12]annulenes 1 and 2 and the corresponding dodecadehydro[18]annulenes 4 and 5 were prepared by oxidative Hay coupling. X-Ray crystal-structure analyses of (i-Pr)₃Si-protected 2 and Me₃Si-protected 4 showed that both annulene perimeters are perfectly planar. Electronic absorption spectral comparisons provided strong evidence that the macro rings in the deep-purple-colored 1 and 2 are antiaromatic (4n π-electrons), whereas those in yellow 4 and 5 are aromatic ((4n + 2) π-electrons). Although unstable in solution, the antiaromatic compound 2 gave high-melting crystals in which the individual octadehydro[12]annulene chromophores are isolated and stabilized in a matrix-type environment formed by the bulky (i-Pr)₃Si groups. Electrochemical studies demonstrated that the antiaromatic octadehydro[12]annulene 2 undergoes two stepwise one-electron reductions more readily that the aromatic chromophore 5 . This redox behavior is best explained by the formation of an aromatic (4n + 2) π-electron dianion from 2 , whereas 5 loses its aromaticity upon reduction. The Me₃Si derivative 4 was deprotected with borax in MeOH/THF to give the highly unstable hexaethynyl-dodecadehydro[18]annulene 6 , a C₃₀H₆ isomer and macrocyclic precursor to a two-dimensional all-C-network. Deprotection of 2 did not give isolable amounts of tetraethynyl-octadehydro[12]annulene 3 due to the extreme instability of the latter. Starting from dimeric and trimeric acyclic tetraethynylethene oligomers, a series of expanded radialenes were obtained. They possess large C-cores with silylethynyl-protected peripheral valences and can be viewed as persilylated C₄₀ ( 7 ), C₅₀ ( 8 ), and C₆₀ ( 9 ) isomers. These expanded C-sheets are high-melting, highly stable, soluble materials which were readily characterized by laser-desorption time-of-flight (LD-TOF) mass spectrometry. Due to inefficient macrocyclic cross-conjugation and/or non-planarity, the extent of π-electron delocalization in 7 – 9 is limited to the longest linearly conjugated π-electron fragment. In agreement with these properties, all three expanded radialenes exhibited similar redox behavior; they are difficult to oxidize but undergo several reversible one-electron reductions in similar potential ranges. Presumably, the reduced π-electron delocalization is also at the origin of the particularly high stability of 7 – 9 .     

新型—维锯齿链状聚金属氧酸盐配位聚合物［｛La(DMSO)_6(H_2O)}·(PMo_(12)O_(40))·H_2O］_n的合成、结构及表征

以a-H_3PMo_(12)O_(40)·nH_2O, La_2O_3和二甲基亚砜（DMSO）为原料，在 乙腈和水的混合溶剂中制得了一维锯齿链状配位聚合物［｛La(DMSO)_6(H_2O)}· (PMo_(12)O_(40))·H_2O］_n,X射线单晶衍射结果表明，聚合物中金属配阳离子与 杂多阴离子骨架通过Mo-O_d-La-O_d-Mo相连并形成一维无限链，每一个不对称结构 单元中含一个结晶水，La~(3+)的配位数为九，三帽三棱柱构型，配位氧原子分别 来自6个DMSO分子，1个H_2O分子和2个相邻杂多阴离子的端氧，晶体氧于单斜晶系 ，P2_1/c空间群，a=1.3916(3)nm,b=1.7058(3)nm,c=2.4750(5)nm,β=99.16(3)~° ,Z=4,V=5.800(2)nm~3,D_c=2.825g/cm~3,R_1=0.0446,wR_2=0.0871,IR光谱和X射线 单晶衍射结果一致表明，在固态条件下配阳离子和杂多阴离子之间存在相互作用， UV光谱表明，在稀的水溶液中，由于溶剂化作用，杂多阴离子与配阳离子处于解离 状态，热性质研究表明，形成标题化合物后，杂多阴离子的热稳定性与磷钼酸相比 明显增强。     

Ruthenium complexes of hexakis(cyanophenyl)[3]radialenes and their di(cyanophenyl)methane precursors: synthesis,photophysical, and electrochemical properties

The coordination chemistry of cross-conjugated ligands and the effect of cross-conjugation on the nature of metal–metal and metal–ligand interactions have received limited attention. To explore the effects of cross-conjugation eight ruthenium complexes were synthesized, mononuclear complexes of two isomeric cross-conjugated [3]radialenes [RuCp(PPh₃)₂(L)]PF₆ and [{RuCp*(dppe)}(L)]PF₆ (L?=?hexakis(4-cyanophenyl)[3]radialene, 2; hexakis(3-cyanophenyl)[3]radialene, 3), and dinuclear complexes [{RuCp(PPh₃)₂}₂(L)](PF₆)₂ and [{RuCp*(dppe)}₂(L)](PF₆)₂ of the diarylmethane precursors (L?=?4,4′-dicyanodiphenylmethane, 4; 3,3′-dicyanodiphenylmethane, 5) to the [3]radialenes. Considerable synthetic challenges allowed only clean isolation of mononuclear complexes of the multidentate radialenes 2 and 3. As expected, coordinating a positively charged metal induces a red shift for the π–π* transition in complexes of ligand 2, but unexpectedly a blue shift for the same transition in complexes of 3 was observed. This points to conformational differences for the [3]radialene in the ruthenium complexes of the para- (2) versus meta- (3) substituted hexaaryl[3]radialenes. Cyclic voltammetry indicates that the methylene spacer in 4 and 5 does not enable any interaction between metal centers and the absorption behavior is essentially as observed for [Ru(NCPh)(PPh₃)₂Cp]PF₆ and [Ru(NCPh)(dppe)Cp*]PF₆ but generally with a slight red shift in absorbance maxima.     

Solvent‐assisted planar structure of a stilbene‐based salicylhydrazone compound: crystal structure,solvent‐ and aggregation‐induced emission,and switchable luminescence colouration

A novel stilbene‐based salicylhydrazone compound {systematic name: (E)‐4,4′‐(ethene‐1,2‐diyl)bis[(N′E)‐N′‐(2‐hydroxybenzylidene)benzohydrazide] dimethyl sulfoxide disolvate, C₃₀H₂₄N₄O₄·2C₂H₆OS or L·2DMSO} was synthesized and characterized by single‐crystal X‐ray diffraction, powder X‐ray diffraction and luminescence spectroscopy. The title compound crystallizes in the monoclinic space group P2₁/c, with half a symmetry‐independent L molecule and one dimethyl sulfoxide (DMSO) solvent molecule in the asymmetric unit. The L molecule adopts an almost planar structure, with a small dihedral angle between the planes of the stilbene and salicylhydrazone groups. There are multiple π–π stacking interactions between adjacent L molecules. The DMSO solvent molecules act as proton donors and acceptors, forming hydrogen bonds of various strengths with the L molecules. In addition, the geometry optimization of a single molecule of L and its luminescence properties either in solution, as a solvated solid or as a desolvated solid were studied. The compound shows an aggregation‐induced emission (AIE) effect and exhibits switchable luminescence colouration in the solid state by the simple removal or re‐addition of the DMSO solvent.     

Modified expanded corrole-ferrocene conjugates: syntheses, structure and properties

Syntheses, characterization and properties of expanded corrole-ferrocene conjugates are reported. Ferrocenyl group are covalently linked to the corrole macrocycle through three different spacers groups. The synthetic strategy involved prior insertion of ferrocene with spacers to the dipyrromethane unit followed by a "3+2" acid-catalyzed oxidative coupling methodology. The optical and emission data of the expanded corrole-ferrocene conjugates depend on the nature and length of the spacer groups and the maximum effects are seen where ferrocene is directly linked to the meso carbon of macrocycle. The single crystal X-ray structure of two expanded corrole-ferrocene conjugates; [22]pentaphyrin (1.1.0.1.0) with different meso substituents, clearly reveal shortening of the C-C bond length linking the meso carbon and the aryl substituent containing the ferrocene moiety relative to meso aryl substituents without ferrocene. The results suggest that an electronic interaction between the two pi systems. Electrochemical data reveal harder oxidation for the ferrocene unit in the conjugates relative to free ferrocene; this suggests the electron donating nature of the ferrocene. The first corrole ring oxidation shows easier oxidation relative to 1 and the magnitude of shifts in potential is inversely proportional to the length of spacer. The molecular first hyperpolarizabilities (beta) measured at 1064 nm by HRS method vary in the range 20-32x10(-30) esu and imply that the beta values can be increased by enhancing the number of mobile electrons in the conjugation. The conjugates form 1:1 metal complex with the Rh(I) where rhodium is coordinated to one amino and one imino nitrogen of the dipyrromethane unit.     

Synthesis, characterization and biological activities of some new organotin(IV) derivatives: Crystal structure of [(Sn Ph3) (OOCC6H4OH)] and [(SnMe3)2 (OOC)2C6Cl4 (DMSO)2]

Some new organotin(IV) carboxylates 1-3 of 2-hydroxybenzoic acid (L_A) and 4-6 of 2,3,4,5-tetrachloro-6-(methoxycarbonyl) benzoic acid (L_B) have been synthesized, respectively, by the esterification of triorganotin oxide/hydroxide with the corresponding acids in an appropriate mole ratios. Multinuclear NMR (¹H, ¹³C and ¹¹⁹Sn), IR and X-ray crystallographic studies were carried out to elucidate their structures both in solution and in solid state. The X-ray crystallographic data for 3 was recollected at low temperature. The compound 4 was dissolved in DMSO and a new compound 4 · 2DMSO [(SnMe₃)₂(OOC)₂C₆Cl₄(DMSO)₂] was crystallized out. The structure shows that two Sn moieties are attached to the ligand (L_B) through two carboxylic groups. The two molecules of DMSO are coordinated to each of the Sn atoms via oxygen atom to terminate the conventional polymeric chain of trimethyl carboxylates to a discrete molecule, having trigonal bipyramidal geometry around the Sn atoms. Some of the synthesized compounds exhibited significant antifungal activities and have a potential to be used as drugs.     

A new triol host framework and the remarkable crystal structure of its DMSO inclusion complex

A new trigonal host molecule 1 featuring three 4-(9-hydroxy-9-fluorenyl)phenyl units symmetrically attached to a benzene core was synthesized and is shown to yield a 1:3 (host:guest) crystalline inclusion compound with DMSO (1a). The crystal structure of 1a is distinguished by a rare case of piedfort arrangement of host molecules and a unique hexameric cluster formation of DMSO.     

Twinning by merohedry in bis(4‐methoxyphenyl)tellurium(IV) diiodide dimethyl sulfoxide hemisolvate

Green crystals of the title compound, C₁₄H₁₄I₂O₂Te·0.5C₂H₆OS, space group P3₂, show twinning by merohedry (class II). The asymmetric unit contains two organotellurium molecules and one dimethyl sulfoxide (DMSO) molecule. The crystal structure displays secondary Te...I and Te...O(DMSO) bonds that lead to [(4‐MeOC₆H₄)₂TeI₂]₂·DMSO supramolecular units in which the two independent organotellurium molecules are bridged by the DMSO O atom. In addition to these secondary bonds, I...I interactions link translationally equivalent organotellurium molecules to form nearly linear ...I—Te—I...I—Te—I... chains. These chains are crosslinked, forming two‐dimensional arrays parallel to (001). The crystal packing consists of a stacking of these sheets, which are related by the 3₂ axis. This study describes an unusual dimeric arrangement of X—Te—X groups.     

Crystal Structure,Thermal Behavior and Luminescence of a One-dimensional Coordination Polymer [Zn（4-CPOA）（Phen）（H2O）]n

A novel coordination polymer of [Zn（4-CPOA）（Phen）（H2O）]n （C21H16N2O6Zn,1,4-CPOA = 4-carboxylato-phenoxyacetate dianion and Phen = 1,10-phenanthroline） has been synthesized and characterized by elemental analysis,IR,TG,PL and single-crystal X-ray diffraction. The crystal crystallizes in the triclinic system,space group of P1 with a = 9.622（3）,b = 9.631（3）,c = 11.526（4）A,α = 67.719（5）,β = 71.203（5）,γ = 83.552（6）o,V = 935.5（5） A^3,Z = 2,Dc = 1.625 g/cm^3,μ = 1.357 mm^-1 and F（000） = 468. The Zn（II） ion is surrounded by three carboxylate O atoms from two different 4-CPOA groups,two N atoms from the Phen ligand and one water molecule,forming a distorted octahedral coordination configuration. The Zn（II） ions were alternately interlinked by carboxylate groups of 4-CPOA with chelating bisbidentate and monodentate modes into a one-dimensional zigzag chain having an intrachain distance of ca. 9.631（1） . Under the direction of supramolecular recognition and attraction,the adjacent chains yield a double-stranded chain through π-π stacking between the phen ligands,which was further expanded into a 2-D framework via strong C–H–π interaction （ca. 2.95（1） ） between the 4-CPOA ligands and into a 3-D supramolecular network by strong hydrogen bond between terminal water molecule and carboxyl group. TG/DTG shows that its chain skeleton is thermally stable up to 419 oC and the blue fluorescent emission of the complex was determined at 471 nm in a solid state with its long decay lifetime of 1.83 ns.     

Hexakis(4-(N-butylpyridylium))benzene: a six-electron organic redox system

The cobalt-catalyzed cyclotrimerization of bis(4-pyridyl)acetylene affords hexakis(4-pyridyl)benzene in moderate yield. Alkylation with n-butyltriflate gives hexakis(4-(N-butylpyridylium))benzene triflate (1 6+), which can be reduced with Na/Hg in DMF to neutral 10. A single-crystal X-ray diffraction structure reveals that 1 0 has a chair-cyclohexane-like core and a [6]radialene structure. Cyclic voltammetry shows that 1 6+ is reversibly reduced to 1 2+ in one four-electron step and 1 2+ is reversibly reduced to 1 0 in one two-electron step. A reduction by four electrons at one potential is unprecedented for a molecule in which the electrochemically active centers are in electronic communication. The large structural transformation from 1 6+ to 1 0 is responsible for the "potential inversion" in the cyclic voltammetry, and DFT calculations suggest a possible structure for the stable intermediate 1 2+. A comparison is made to the electrochemistry and structural transformations in a previously prepared [4]radialene analogue of 1 0.     

An expanded cavity hexaamine cage for copper(II)

The crystal structure of the bicyclic hexaamine complex [Cu(fac-Me5-tricosane-N6)](ClO4)2.H2O (fac-Me5-tricosane-N6 = facial-1,5,9,13,20-pentamethyl-3,7,11,15,18,22-hexaazabicyclo[7.7.7]tricosane) at 100 K defines an apparently tetragonally compressed octahedral geometry, which is attributed to a combination of dynamic interconversion and static disorder between two tetragonally elongated structures sharing a common short axis. This structure is fluxional at 60 K and above as shown by EPR spectroscopy. Aqueous cyclic voltammetry reveals that a remarkably stable Cu(I) form of the complex is stabilised by the encapsulating nature of the expanded cage ligand.     

一种镧系-过渡金属二维氰桥配合物[Nd(DMSO)2(H2O)2][Ni(CN)4]Cl(DMSO=二甲亚砜)的合成和晶体结构(英)

The cyano-bridged bimetallic complex [Nd(DMSO)₂(H₂O)₂][Ni(CN)₄]Cl with two-dimensional gridding molecule structure was synthesized and characterized. In the complex all four cyano groups of unit Ni(CN)₄^2- are bound to Nd³⁺ ions. The crystal data for the title complex: monoclinic, space group P2₁/c, a=0.780 0(3) nm, b=1.509 7(6) nm, c=1.683 2(6) nm, β=115.231(14)°, Z=4, μ=4.311 mm^-1, final R₁=0.020 9, wR₂=0.045 4. CCDC: 272214.     

Anthracene Based Bulky Diol Hosts. Crystal Structures of a Free Host and of Inclusion Compounds with Dipolar Guests

X-ray crystal structures are reported of a free host compound 1, comprising two diphenylmethanol terminal groups attached to a central 9,10-ethynyl substituted anthracene unit, and of three inclusion compounds of a fluoren-9-ol substituted analogous host 2 with acetone, dimethyl sulphoxide (DMSO) and dimethylformamide (DMF) as guest, respectively. Despite the presence of two hydroxyl groups in 1, there is no O–H...O hydrogen bond between the molecules in the guest free crystal – only weaker C–H...O interactions and van der Waals' type connections. In the inclusion compounds of 2, H-bonded 1:2 host–guest associates are formed, where each of the host hydroxyl groups binds to a guest oxygen atom. The orientations of the host–guest connections in these complexes vary, being E for acetone and Z for both DMSO and DMF guests, relative to the host anthracene unit. The DMSO and DMF inclusion compounds of 2 proved to be isostructural.