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1.
A novel type of liquid crystalline system, namely 5-[4-(4-methoxyphenylazo)phenyloxyalkyloxy]isophthalic acidhydrazides ( Dn , n = 3, 6, 10) was designed and synthesized. The FTIR spectra of the Dn compounds were examined in the range 4000-1000 cm ?1 at different temperatures. The results showed that the stretching vibration frequencies of the NH and C=O groups, and the NH 2 deformation shifted to lower frequencies with decrease of temperature, while out-of-plane NH bending shifted slightly to higher frequency. Intermolecular hydrogen bonding between NH, NH 2 and C=O groups is proposed and the schematic supramolecular Dn structure is given. This may explain the higher Dn transitional temperatures and their smectic phase behaviour compared with that of 5-[4-(4-methoxyphenylazo)phenyloxyalkyloxy]isophthalic acid diethyl esters. 相似文献
2.
The carbonyl derivatized bis(alkyne) O=C(4-C 6H 4OCH 2CCH) 2 was converted into the imine derivatives RN=C(4-C 6H 4OCH 2CCH) 2 [R=OH, NHC(O)NH 2, NHC 6H 3-2,4-(NO 2) 2] and into the 4-bromomethyl-1,3-dioxolane derivative BrCH 2C 2H 3O 2C(4-C 6H 4OCH 2CCH) 2. The alkyne units in these compounds react with [AuCl(SMe 2)] in the presence of base to form the corresponding digold(I) diacetylide complexes, that exist as insoluble oligomers or polymers. They reacted with the diphosphines Ph 2PZPPh 2 [Z=CC, trans-HC=CH and (CH 2) n, n=3–5] to give macrocyclic gold(I) complexes of the type [Au 2(μ-LL)(μ-PP)], where LL is the diacetylide and PP the diphosphine ligand. The ability of these macrocyclic complexes to self-assemble to [2]catenanes has been studied. The ketone and imine derivatives do not form [2]catenanes because the orientation of the aryl groups is unfavorable, but the 1,3-dioxolane derivatives may catenate if the ring size is optimum. 相似文献
3.
The reaction of [Cp 2MoH 2] and AgBF 4 with the dithio ligands Na(S 2CPh) and K(S 2CO iPr) afforded the complexes [(Cp 2MoH 2AgS 2CPh) 2] (1) and [(Cp 2MoH 2AgS 2CO iPr) 2] (2). Using the monothio ligands Na(SC(O)Ph), K(SC(O)CH 3) and Na(S(NHPh)C=C(CN) 2) the complexes [(Cp 2MoH 2AgSC(O)Ph) 2] (3), [((Cp 2MoH 2) 2(AgSC(O)CH 3) 3) n] (4) and [(Cp 2MoH 2) 2AgS(NHPh)C=C(CN) 2] (6) were formed. The reaction of thiobenzamide and [(Cp 2MoH 2) 2AgCl] gave the complex [(Cp 2MoH 2Ag(Cl)S(NH 2)CPh) 2] (5). Complexes 1 and 2 have a dimeric structure with the two dithio ligands bridging the two silver atoms. Complex 3 is also a dimer, however, the monothio ligands are coordinated with their single sulphur atoms to the silver atoms. In the polymer 4 the thioacetate ligand has the same bonding mode as in 3. The three-dimensional structure of 4 is built-up of parallel strings. In the dimer 5 the thiobenzamide ligands bind with the sulphur atom to a silver atom each. Complex 6 has a monomeric structure in which the silver atom is coordinated to two [Cp 2MoH 2] ligands and to the sulphur atom of the S(NHPh)C=C(CN) 2 ligand. Compounds 1–6 were characterised analytically and spectroscopically and the structures were determined by single crystal X-ray analyses. 相似文献
4.
采用密度泛函理论(DFT)对钌掺杂的铂团簇阳离子([Pt nRu m] +, m + n = 3, n ≥ 1)活化甲醇C―H和O―H键反应进行了理论研究;探讨了电荷对[Pt nRu m]团簇反应活性的影响。电荷分析表明:(1) [Pt 3] +团簇中正电荷在三个Pt原子上均匀分布;掺杂Ru原子后,正电荷主要分布在Ru原子上; (2)首先活化C―H键时[Pt nRu m] +的反应活性比[Pt nRu m]明显提高;首先活化O―H键时只有[Pt 3] +比[Pt 3]团簇的反应活性有明显提高。本研究可为金属团簇调控的C―H键和O―H键的活化提供更深入的理解。 相似文献
5.
A series of N-[4'-(dodecyloxy)resorcylidene]-4-(RO*)-anilines ( HLn n = 1, R*O = (-)- cis-myrtanyl; n = 2, R*O = (-)-menthyl; n = 3, R*O = S-(-)-β-citronellyl; n = 4, R*O = R-(-)-2-octyl) has been synthesized and the mesomorphic properties investigated. These ligands are able to chelate a metal atom; accordingly three different series of palladium complexes, [(Ln)Pd(Ln)], [(Ln)Pd(Azoxy-6)] and [(L 3)Pd(Ph-Py n)] (where Azoxy-6 and PhPy n are cyclopalladated 4,4'-dihexyloxyazoxybenzene and 5-substituted-2-(4-substituted-phenyl)pyrimidine, respectively) have been prepared. The mesogenic HL3 and HL4 ligands exhibit a S* C phase, retained in [(L 3)Pd(L 3)], which changes to a cholesteric phase in [(L 4)Pd(L 4)] and becomes the more ordered S* H phase in the [(Ln)Pd(Azoxy-6)] ( n = 3,4) derivatives. In contrast, in the [(L 3)Pd(Ph-Py n)] compounds the mesomorphic phase is a S A phase. 相似文献
6.
采用共沉淀法制备了高比表面积的Mn xCo 3−xO 4球形催化剂,研究了NH 3选择性催化还原NO x性能。Mn-Co金属氧化物具有尖晶石结构,随着Co含量的增加,晶体结构由四方相转变为立方相。高浓度的表面活性氧物种和变价元素的强有效电子转移(Co 3+ + Mn 3+ ↔ Co 2+ + Mn 4+)有利于提高Mn xCo 3−xO 4 ( x = 1.0、1.5、2.0)尖晶型石催化剂的氧化还原能力,催化剂表面的Mn富集作用形成了氧缺陷结构和丰富的表面活性位点,进一步促进SCR脱硝反应,呈现出优异的催化性能。Co tet(CoMn) octO 4晶体结构中,Mn离子(Mn 3+和Mn 4+,以三价锰为主)和部分Co离子被配置到八面体中心,这些物种作为活性位点存在着较强的电子转移交互作用,该构型对促进低温脱硝活性和保护活性位点耐受SO 2毒害具有重要的意义。Mn-Co尖晶石表面的NH 3-SCR脱硝反应过程主要遵循Eley-Rideal反应机理,即吸附态NH 3与气态NO (或NO 2)的反应路径。随着反应温度的增加,反应生成的NH 4NO 3中间体很可能转化为NH 4NO 2物种,进而分解为N 2,提高了催化剂的氮气选择性。 相似文献
7.
Polyoxoanions of tungsten, molybdenum, and vanadium have been the subject of interest since their wide variety of compositions, structures, and properties give rise to numerous important applications [1]. From the NH 4VO 3/Na 2S x (or (NH 4) 2S x) reaction system we synthesized several spherical octadecavanadates with Na +,K +, NH 4+ or I encapsulated using hydrothermal method. These complexes include (NH 4) 11[V 18O 42(Na)]·(H 2O) 20 1; (NH 4) 11[V 18O 42(K)]·(H 2O) 6, 2; (NH 4) 10(Na)[V 18O 42(Na)]·(H 2O) 26, 3; (NH 4) 11[V 18O 42(NH4]·(H 2O) 20, 4; and (NH 4) 20(I) 7[V 18O 42(I)]·(H 2O) 12, 5, in which the structures of 1, 2, 3, and 5 have been determined by X-ray analyses. In the analogous reaction system of (NH 4) 2MoS 4/(NH 4) 2S x, we also obtained one ellipsoidal octadecamolybdate, (NH 4) 4[Mo 18O 54(2SO 4)]·(H 2O) 4, 6 with a standard Wells-Dawson structure [2]. The Ortep drawings of the two kinds of structures are viewed as follows. 相似文献
8.
The title cobalt(III) complexes have been investigated by polarized absorption and Raman spectroscopies of the single crystals. The symmetry properties of the d-electron orbitals and of the vibrational modes attributable to the Raman bands of trans(Cl 2)-[CoCl 2(NH 3) n(H 2O) 4−n]Cl complexes ( n = 2, 3, or 4) were examined to elucidated the peculiar observation that ligand substitution causes no splitting of the 15 200-cm −1 absorption band and the 250-cm −1 Raman band. Effects of replacing the NH 3 ligand with H 2O on the electronic structure, atom–atom force constants and vibrational modes of these complex ions are briefly described. 相似文献
9.
The bimetallic [Pt(NH 3) 4] 2[W(CN) 8][NO 3]·2H 2O is characterised by single-crystal X-ray diffraction [S.G. P2 1/ m(11), a=8.0418(7), b=19.122(2), c=9.0812(6) Å, Z=2]. All platinum centres have the square-plane D4h geometry with average dimensions Pt(1)–N 2.042(2) and Pt(2)–N 2.037(10) Å. The octacyanotungstate anion has the square-antiprismatic D4d configuration with average dimensions W(1)–C 2.164(13), C–N 1.140(12), W(1)–N 3.303(5) Å. The structure exhibits two different mutual orientations of Pt versus W units resulting in Pt(2)–W(1), W(1) * separations of 4.77(2), 4.55(2) * and Pt(1)–W(1) of 6.331(8) Å. A centrosymmetric structure reveals groups of two distinct columns: the first is formed by intercalated NO 3− between parallel [Pt(1)(NH 3) 4] 2+ planes and the second consists of [W(CN) 8] 3− interlayered by, parallel to square faces of W-antiprisms, [Pt(2)(NH 3) 4] 2+. The structure is stabilised through a three-dimensional hydrogen bond network via nitrogen atoms of cyanide ligands, hydrogen atoms of NH 3 ligands, water molecules and oxygen atoms of NO 3− counteranions. The vibrational pattern and the range of ν(CN) frequencies attributable to the electronic environment of W(V) and W(IV) are consistent with the ground state Pt(II)↔W(V) charge transfer. 相似文献
10.
Three novel series of monomers, namely n-1-bromo-[4-(4-methoxyphenylazo)phenyloxy]-alkanes (Bn, n = 3, 6, 10), n-[4-(4-methoxyphenylazo)phenyloxy]alkyloxy-4-methoxybenzene (Cn, n = 3, 6, 10) and n-[4-(4-methoxyphenylazo)phenyloxy]alkyloxy-[4-methoxy-2,5-bis(chloromethyl)]benzene (Dn, n = 3, 6, 10) were synthesized and characterized with FTIR, 1H NMR, UV-visible and fluorescence spectroscopy. Their thermal behaviour was studied by different scanning calorimetry and polarizing optical microscopy. The results show that B3, B6 and C6 exhibit monotropic nematic liquid crystalline behaviour. 相似文献
11.
Complexes trans-[PtX(L)(PPh 3) 2]A [1: X = CF 3; A = BF 4; L = NCNH 2, NCNMe 2, NCNEt 2, or NCNC(NH 2) 2. 2: X = Cl; A = BPh 4; L = NCNMe 2 or NCNEt 2] and cis-[PtCl(L)(PPh 3) 2][BPh 4] [3: L = NCNH 2 or NCNC(NH 2) 2], which appear to be the first cyanamide or cyanoguanidine complexes of platinum to be reported, have been prepared by treatment of trans-[PtBr(CF 3)(PPh 3) 2] (in CH 2Cl 2/acetone and in the presence of Ag[BF 4]) or of cis-[PtCl 2(PPh 3) 2] (in THF and in the presence of Na[BPh 4]), respectively, with the appropriate substrate. In KBr pellets or in solution 1 (L = NCNMe 2 or NCNEt 2) undergoes ready replacement of the organocyanamide (under the trans influence of CF 3) by bromide to regenerate trans-(PtBr(CF 3)(PPh 3) 2]. The X-ray structure of 1 (X = CF 3, A = BF 4, L = NCNEt 2) is also reported, and shows the presence of two apical intramolecular contacts of the metal with two ortho-hydrogen atoms of the phosphines, whereas the amine N atom of the diethylcyanamide is trigonal planar in the linear NCN framework with a delocalized π system. 相似文献
12.
Two polymeric complexes, [Cu 2(btec)(phen) 2] n·(H 2O) n (1) and [Cd 4(btec) 2(phen) 4(H 2O) 4] n (2) (H 4btec=1,2,4,5-benzenetetracarboxylic acid; PHEN=1,10-phenanthroline), were synthesized by solvothermal reactions at 140 °C. Both complex 1 and 2 possess infinite double-chain structures, in which each Cu(II) center has a tetrahedral configuration and the Cd(II) centers adopt triangular prismatic and square-based pyramidal configurations simultaneously. The inter-chain face to face π–π interactions among the aromatic rings of phen and the hydrogen bond interactions between aqua molecules and carboxyl O atoms result in 3-D networks in the two complexes. The ESR spectra study of complex 1 shows that there is negligibly small long-range super-exchange interactions between the Cu(II) atoms via benzenecarboxylate bridging. 相似文献
13.
Reaction of hexaamminecobalt(III) chloride with the silver salt of methanesulphonic acid in aqueous medium (1:3 molar ratio) forms hexaamminecobalt(III) methanesulphonate, [Co(NH 3) 6](CH 3SO 3) 3, in high yield. This cobalt(III) complex has been characterized by spectroscopic techniques (UV/visible, IR and NMR) and its solubility product determined. The X-ray crystal structure shows that the [Co(NH 3) 6] 3+ cations interact at the second sphere by sharing edges with the anions, via N–H O hydrogen bonds. The structure is related to that of [Co(NH 3) 6]Cl(CH 3SO 3) 2, but is modified to accommodate additional anions in place of Cl −. 相似文献
14.
Recent results (post-1990) on the synthesis and structures of bis(trimethylsilyl)methyls M(CHR 2) m (R = SiMe 3) of metals and metalloids M are described, including those of the crystalline lipophilic [Na(μ-CHR 2)] ∞, [Rb(μ-CHR 2)(PMDETA)] 2, K 4(CHR 2) 4(PMDETA) 2, [Mg(CHR 2)(μ-CHR 2)] ∞, P(CHR 2) 2 (gaseous) and P 2(CHR 2) 4, [Yb(CHR 2) 2(OEt 2) 2] and [{Yb(CR 3)(μ-OEt)(OEt 2)} 2]; earlier information on other M(CHR 2) m complexes and some of their adducts is tabulated. Treatment of M(CHR 2) (M = Li or K) with four different nitriles gave the X-ray-characterized azaallyls or β-diketinimates
,
and
(LL′ = N(R)C( tBu)CHR, L′L′ = N(R)C(Ph)C(H)C(Ph)NR, LL″ = N(R)C(Ph)NC(H)C(Ph)CHR, R = SiMe 3 and Ar = C 6H 3Me 2-2,5). The two lithium reagents were convenient sources of other metal azaallyls or β-diketinimates, including those of K, Co(II), Zr(IV), Sn(IV), Yb(II), Hf(IV) and U(VI)/U(III). Complexes having one or more of the bulky ligands [LL′] −, [L′L′] −, [LL] −, [LL″] −, [L″L] −, [LL] − and [{N(R)C( tBu)CH} 2C 6H 4-2] 2− are described and characterized (LL = N(H)C(Ph)C(H)C(Ph)NH, L″L = N(R)C( tBu)C(H)C(Ph)NR, LL = N(R)C( tBu)CHPh). Among the features of interest are (i) the contrasting tetrahedral or square-planar geometry for
and
, respectively, and (ii) olefin-polymerization catalytic activity of some of the zirconium(IV) chlorides. 相似文献
15.
The syntheses of the 1,3,5-trimethyl- and tri- tert-butyl-1,3,5-triazacyclohexane-supported imido complexes [M(NR)(R′ 3tach)Cl 2] (M = Ti or Zr (NMR only); R = Bu t or 2,6-C 6H 3Pr i2; R′ = Me or Bu t) are reported, along with that of the thermally robust dibenzyl derivative [Ti(NBu t)(Me 3tach)(CH 2Ph) 2]. The tert-butylimido ligand in [Ti(NBu t)(Me 3tach)Cl 2] undergoes exchange with ArNH 2 (Ar = 4-C 6H 4Me or 2,6-C 6H 4Me or 2,6-C 6H 3Pr i2) to form the corresponding arylimides [Ti(NAr)(Me 3tach)Cl 2]. The Me 3tach ring in [Ti(NR)(Me 3tach)Cl 2] undergoes slow exchange with Bu t3tach or Me 3tacn (1,4,7-trimethyl-1,4,7-triazacyclononane) to give the ring-exchanged products [Ti(NR)(Bu t3tach)Cl 2] and [Ti(NR)(Me 3tacn)Cl 2], respectively. The complexes [Ti(NR)(Me 3tach)X 2] (R = Bu t or 2,6-C 6H 3Pr i2; X = Cl or CH 2Ph) exhibit room-temperature dynamic NMR behaviour via an unusual trigonal twist of the facially coordinated Me 3tach ligand, and the activation parameters for these processes have been measured and are discussed. The X-ray structures of [Ti(NR)(Bu t3tach)Cl 2] (R = Bu t or 2,6-C 6H 3Pr i2) and [Ti(NBu t)(Me 3tach)(X) 2] [X= Cl or CH 2Ph) are reported. Me 3tach and Bu t3tach = 1,3,5-trimethyl- and tri- tert-butyl-1,3,5-triazacyclohexane, respectively. 相似文献
16.
Polycatenar saturated macrocycles 1,10-bis[3,4,5-tris(4-dodecyloxy)benzoy1]-1,10-diaza-4,7,13,16-tetrathiacyclo-octadecane ( 3b) and 1,10-bis[3,4-bis(4-dodecyloxy)benzoy1] -1,10-diaza-4,7,13,16-tetrathiacyclo-octadecane ( 3d) reacted with [Pd(MeCN) 4][BF 4] 2 led to the cationic complexes [ 4b][BF 4] 2 and [ 4d][BF 4] 2, respectively. Complexes [ 4b][BF 4] 2 and [ 4d][BF 4] 2 showed smectic mesomorphism on heating as confirmed by small angle X-ray diffraction. A concurrent, irreversible structural change of the complex cations was observed and a tentative explanation is suggested. 相似文献
17.
A new series of 1,1'-disubstituted ferrocene compounds of the type [(η 5-C 5H 4(CH 2) nOC 6H 4C 6H 4CN] 2Fe ( 3a-d, n = 5, 6, 8, 11) incorporating a variable length alkyloxy cyanobiphenyl unit has been prepared and their mesomorphic properties have been investigated. Compounds 3b, c and d exhibit a thermotropic smectic C phase and 3c also exhibits a monotropic smectic A phase over a fairly wide range near ambient temperature. 相似文献
18.
Stable aqueous solutions of the green ion [Co(sa1) 3] 3− (sa1 = dianion, C 6H 4(
)(CO
), of salicylic acid, 2-hydroxybenzoic acid) are obtained from [Co(NH 3) 5 C1]C1 2 and an excess of salicylic acid. Several salts, [C][Co(sa1) 3] have been characterized, where C = [Co(NH 3) 6] 3+ and [M(en) 3] 3+ (M = Co or Rh, EN = 1,2-diamino-ethane). By using (+)-[Rh(en) 3] 3+, optical resolution via less soluble diastereoisomeric salts has been achieved, and isomerization and racemization have been studied. Resolved tris-malonatocobaltate(III) has been used as a model. A novel thermochromism (77-293 K) in solid Δ(+)-[Rhen 3]Λ[Co(sa1) 3 is described. 相似文献
19.
Considered under the aspect of its ambidence, the reactivity of cyanamidonitrate [NO 2NCN] − towards triorganostannyl chlorides was investigated. The reaction products of type R 3Sn-NCN-NO 2 were characterized by 1H-NMR, 13C-NMR, 119Sn-NMR and IR spectroscopy. While cyanamides of the type [R nE(Y)NCN] − (R nE(Y) = RC(O), RC(NCN), R 2 P(O), R 2P(S), R 2P(NCN), RSO 2) are coordinated exclusively either via the terminal nitrogen (monodentately) or via both the nitrile group end on and the chalcogen atom (bidentately), we found N-triorganostannyl-N′-nitro-carbodiimides as the first example in which the NCN group acts as a bidentate bridge with metal-N bonds in 1- and 3-position. For Me 3Sn-NCN-NO 2 the crystal structure was determined. ZusammenfassungUnter dem Aspekt der Ambidenz wurde die Reaktivität von Cyanamidonitrat [NO2NCN]− gegenüber Triorganostannylchloriden untersucht. Die Reaktionsprodukte des Typs R3Sn-NCN-NO2 wurden 1H-NMR-, 13C-NMR-, 119Sn-NMR- sowie IR-spektroskopisch charakterisiert. Während Cyanamide des Typs [RnE(Y)NCN]− (RnE(Y) = RC(O), RC(NCN), R2P(O), R2P(S), R2P(NCN), RSO2) ausschlieβlich über das terminale Stickstoff- (einzähnig) bzw. über das Nitrilstickstoff- und das Chalkogenatom (zweizähnig) gebunden werden, fanden wir mit N-Triorganostannyl-N′-nitro-carbodiimiden erstmalig Beispiele, in denen die NCN-Gruppe zweizähnig verbrückend in 1- und 3-Position koordiniert wird. Für Me3Sn-NCN-NO2 liegt eine Kristallstrukturbestimmung vor. 相似文献
20.
The synthesis of the homoleptic molybdenum imido compound Li 2Mo(NBu t) 4 is reported. The complexes M (NBu t) 2(NHBu t) 2 (M = Mo, W) can be protonated with various strong acids giving neutral species. The X-ray crystal structure of the tungsten complex W (NBu t) 2(NH 2Bu t) 2 (SO 3CF 3) 2 confirms the presence of O-coordinated cis- CF 3SO 3 groups. 相似文献
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