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1.
Different metal perchlorates were screened to catalyze the three‐component reaction of anthranilic acid, triethyl orthoformate and amines to afford quinazolin‐4(3H)‐ones in solvent‐free conditions. Ni(ClO4)2 or Zn(ClO4)2 was demonstrated to be efficient to catalyze the reaction.  相似文献   

2.
The amino substituted bidentate chelating ligand 2‐amino‐5‐(2‐pyridyl)‐1,3,4‐thiadiazole (H2 L ) was used to prepare 3:1‐type coordination compounds of iron(II), cobalt(II) and nickel(II). In the iron(II) perchlorate complex [FeII(H2 L )3](ClO4)2·0.6MeOH·0.9H2O a 1:1 mixture of mer and fac isomers is present whereas [FeII(H2 L )3](BF4)2·MeOH·H2O, [CoII(H2 L )3](ClO4)2·2H2O and [NiII(H2 L )3](ClO4)2·MeOH·H2O feature merely mer derivatives. Moessbauer spectroscopy and variable temperature magnetic measurements revealed the [FeII(H2 L )3]2+ complex core to exist in the low‐spin state, whereas the [CoII(H2 L )3]2+ complex core resides in its high‐spin state, even at very low temperatures.  相似文献   

3.
Three novel copper(II) complex [Cu2(bpa)(μ‐PhCO2)](ClO4)2 ( 1 ), [Cu2(bpa) (μ‐pyz)](ClO4)2 ( 2 ), and [Cu(Hbpa)](ClO4)2·2CH3CN ( 3 ) have been synthesized by the reaction of Hbpa with Cu(ClO4)2·6H2O in the presence and absence of exogenous ligands (where Hbpa = N, N'‐bis(picolinidene‐N‐oxide)‐2‐hydroxy‐1, 3‐diamino‐propane). Molecular structures of these compounds have been elucidated by single crystal X‐ray diffraction. 1 and 2 are both binuclear complexes in which two copper atoms are linked by the endogenous alkoxide oxygen and the exogenous benzoate and pyrazolate ligands, respectively. 3 consists of a one‐dimensional polymeric structure, in which Hbpa functions as a bridging mode.  相似文献   

4.
A substituted 2,6‐bis(pyrazol‐3‐yl)pyridine (3‐bpp) ligand, H4L, created to facilitate intermolecular interactions in the solid, has been used to obtain four novel FeII complexes: [Fe(H4L)2](ClO4)2 ? 2 CH3NO2 ? 2 H2O, [Fe(H4L)(H2LBF2)](BF4) ? 5 C3H6O (H2LBF2 is an in situ modified version of H4L), [Fe(H4L)2](ClO4)2 ? 2 C3H7OH and [Fe(H4L)2](ClO4)2 ? 4 C2H5OH. Changing of spin‐inactive components (solvents, anions or distant ligand substituents) causes differences to the coordination geometry of the metal that are key to the magnetic proper‐ ties. Magnetic measurements show that, contrary to the previously published complex [Fe(H4L)2](ClO4)2 ? H2O ? 2 CH3COCH3, the newly synthesised compounds remain in the high‐spin (HS) state at all temperatures (5–300 K). A member of the known family of FeII/3‐bpp complexes, [Fe(3‐bpp)2](ClO4)2 ? 1.75 CH3COCH3 ? 1.5 Et2O, has also been prepared and characterised structurally. In the bulk, this compound exhibits a gradual and incomplete spin transition near 205 K. The single‐crystal structure is consistent with it being HS at 250 K and partially low spin at 90 K. Structural analysis of all these compounds reveals that the exact configuration of intermolecular interactions affects dramatically the local geometry at the metal, which ultimately has a strong influence on the magnetic properties. Along this line, the geometry of FeII in all published 3‐bpp compounds of known structure has been examined, both by calculating various distortion indices (Σ, Θ, θ and Φ) and by continuous shape measures (CShMs). The results reveal correlations between some of these parameters and indicate that the distortions from octahedral geometry observed on HS systems are mainly due to strains arising from intermolecular interactions. As previously suggested with other related compounds, we observe here that strongly HS‐distorted systems have a larger tendency to remain in that state.  相似文献   

5.
Two polymorphs of the spin crossover (SCO) compound [Fe(1,3‐bpp)2](ClO4)2 ( 1 and 2 ; 1,3‐bpp=2‐(pyrazol‐1‐yl)‐6‐(pyrazol‐3‐yl)pyridine) were prepared using a novel, stepwise procedure. Crystals of 1 deposit from dry solvents, while 2 is obtained from a solid‐state procedure, by sequentially removing lattice H2O molecules from the solvatomorph [Fe(1,3‐bpp)2](ClO4)2?2 H2O ( 2 ?2 H2O), using single‐crystal‐to‐single‐crystal (SCSC) transformations. Hydrate 2 ?2 H2O is obtained through the same reaction as 1 , now with 2.5 % of water added. Compounds 2 and 2 ?2 H2O are unstable in the atmosphere and absorb or lose one equivalent of water, respectively, to both yield the stable solvatomorph [Fe(1,3‐bpp)2](ClO4)2?H2O ( 2 ?H2O), also following SCSC processes. The four derivatives have been characterised by single‐crystal X‐ray diffraction (SCXRD). Furthermore, the homogeneity of the various compounds as well as their SCSC interconversions have been confirmed by powder X‐ray diffraction (PXRD). Polymorphs 1 and 2 exhibit abrupt SCO behaviour near room temperature with T1/2↑=279/316 K and T1/2↓=276/314 K (near 40 K of shift) and different cooperativity.  相似文献   

6.
A new, one‐pot, simple thermally efficient and solvent‐free method for the preparation of 7‐alkyl‐6H,7H‐naphtho[1′,2′:5,6]pyrano[3,2‐c]chromen‐6‐ones by condensation of β‐naphthol, aromatic aldehydes, and 4‐hydroxycoumarin using Zr(HSO4)4 as a safe and efficient catalyst is described. This method has the advantages of high yields, a cleaner reaction, simple methodology, short reaction times, easy workup, and greener conditions. J. Heterocyclic Chem., (2011).  相似文献   

7.
The title compound, [Cu(ClO4)(C5H6N2)2(C12H12N2)]ClO4, was prepared by in situ partial ligand substitution between 3‐amino­pyridine and 4,4′‐dimethyl‐2,2′‐bipyridine at room temperature. The central copper(II) ion is five‐coordinated by one bidentate 4,4′‐dimethyl‐2,2′‐bipyridine mol­ecule, two monodentate pyridine‐coordinated 3‐amino­pyridine mol­ecules and one apical O atom from the perchlorate counter‐ion. Inter­molecular N—H⋯O and C—H⋯O hydrogen‐bonding inter­actions form a hydrogen‐bond‐sustained network.  相似文献   

8.
1‐(2‐Hydroxyethyl)‐3‐nitro‐1, 2, 4‐triazole (hnt), prepared by alkylation of 3‐nitro‐1, 2, 4‐triazole with 2‐chloroethanol, was found to react with copper(II) chloride and copper(II) perchlorate in acetonitrile/ethanol solutions giving complexes [Cu2(hnt)2Cl4(H2O)2] and[Cu(hnt)2(H2O)3](ClO4)2, respectively. They are the first examples of coordination compounds with a neutral N‐substituted 3‐nitro‐1, 2, 4‐triazole ligand. 1‐(2‐Hydroxyethyl)‐3‐nitro‐1, 2, 4‐triazole and the obtained complexes were characterized by NMR and IR spectroscopy, X‐ray, and thermal analyses. [Cu2(hnt)2Cl4(H2O)2] presents a dinuclear chlorido‐bridged complex in which hnt acts as a chelating bidentate ligand, coordinated to the metal by a nitrogen atom of the triazole ring and an oxygen atom of the nitro group, and the copper atoms are inconsiderably distorted octahedral coordination. [Cu(hnt)2(H2O)3](ClO4)2comprises a mononuclear complex cation, in which two nitrogen atoms of two hnt ligands in trans configuration and three water oxygen atoms form a square pyramidal environment around the copper atom, which is completed to an distorted octahedron with a bifurcated vertex due to two additional elongated Cu–O bonds with two nitro groups. In both complexes, Cu–O bonds with the nitro groups may be considered as semi‐coordinated.  相似文献   

9.
The reaction of (Z)‐2‐[amino(pyridine‐2‐yl)methylene]hydrazonecarbothioamide (HAm4DH) with Mn(ClO4)2·6H2O afforded different mononuclear or polynuclear manganese(II) complexes, the nature of which apparently depended on the solvent used. For example, in ethanol a compound of formula [Mn(HAm4DH)2](ClO4)2 ( 1 ) was obtained, where HAm4DH coordinates as a common tridentate NNS donor, but the [Mn(bpy)2(NCS)2] complex ( 2 ) (bpy = 2,2'‐bipyridine) has also been obtained – probably due to C–N bond cleavage of the thiosemicarbazone. Nevertheless, in a basic aqueous medium [Mn(bpy)3](ClO4)2·0.5bpy ( 3 ) is formed and there is structural evidence for chemical transformations of the thiosemicarbazone promoted by MnII. Thus, the sulfate in {[Mn(py)4Mn(py)2(H2O)2(μ‐SO4)2]·4H2O}n ( 4 ) or sulfate and cyclooctasulfur in [Mn(pta)2(pdo)]4(SO4)2·4H2O·S8] ( 5 ), where pta is 3‐(pyridin‐2‐yl)‐1,2,4‐triazol‐5‐amine and pdo is (2R,4R/2S,4S)‐pentane‐2,4‐diolato, arise from the desulfuration and oxidation of the thiosemicarbazone ligand. The structures of complexes 2 to 5 were established by single‐crystal X‐ray diffraction. The formation of pta is the result of the oxidative cyclization of HAm4DH. In the polynuclear complex 4 , the sulfate acts as an (O,O') bridge between alternating Mn(py)2(H2O)2 and Mn(py)4 centers. In the tetranuclear complex 5 , pta acts as a bischelating ligand through the N‐pyridine and N‐triazole, and pdo act as a bridge between two manganese atoms. It is also noteworthy that in complexes 4 and 5 hydrogen bonds give rise to different self‐assembly behaviour that leads to complicated supramolecular structures.  相似文献   

10.
2,2‐Di­methyl‐5‐[3‐(4‐methyl­phenyl)‐2‐propenyl­idene]‐1,3‐di­ox­ane‐4,6‐dione, C16H16O4, crystallizes in the triclinic space group , with two mol­ecules in the asymmetric unit. These mol­ecules and a centrosymmetrically related pair, linked together by weak C—H?O hydrogen bonds, form a tetramer. 5‐[3‐(4‐Chloro­phenyl)‐2‐propenyl­idene]‐2,2‐di­methyl‐1,3‐dioxane‐4,6‐dione, C15H13ClO4, also crystallizes in the triclinic space group , with one mol­ecule in the asymmetric unit. Centrosymmetrically related mol­ecules are linked together by weak C—H?O hydrogen bonds to form dimers which are further linked by yet another pair of centrosymmetrically related C—H?O hydrogen bonds to form a tube which runs parallel to the a axis.  相似文献   

11.
The reaction of the diazine ligand 3,5‐bis(2‐pyridinyl)‐1,3,4‐oxa­diazole (pod, C12H8N4O), with Cu(CF3SO3)2 or Ni(ClO4)2 afforded the title complexes di­aqua­bis­[3,5‐bis(2‐pyridinyl)‐1,3,4‐oxa­diazole‐N2,N3]copper(II) bis­(tri­fluoro­methane­sul­fon­ate), [Cu(pod)2(H2O)2](CF3SO3)2, and di­aqua­bis­[3,5‐bis(2‐pyridinyl)‐1,3,4‐oxa­diazo­le‐N2,N3]­nickel(II) diperchlorate, [Ni(pod)2(H2O)2](ClO4)2. Both complexes present a crystallographically centrosymmetric mononuclear cation structure which consists of a six‐coordinated CuII or NiII ion with two pod mol­ecules acting as bidentate ligands and two axially coordinated water mol­ecules.  相似文献   

12.
Crystallization of [Cd(S‐thpc12)](ClO4)2·H2O {S‐thpc12 is 1,4,7,10‐tetra­kis[(S)‐2‐hy­drox­y­propyl]‐1,4,7,10‐tetra­aza­cy­clo‐do­dec­ane} in the presence of sodium p‐nitrophenolate forms the title complex, [Cd(C20H44N4O4)](C6H4NO3)(ClO4)·H2O, in which p‐nitrophenolate and water separately hydrogen bond to a different pair of cis‐related pendant hydroxyl groups which, together with the four N atoms, are themselves bound to CdII in an approximately square antiprismatic arrangement. The diastereoselectivity of the complex‐forming process is apparent from the fact that both different disymmetric cations in the asymmetric unit have the same Δ helicity.  相似文献   

13.
The structure of the title compound, [Cu2(C12H24N4O2)(C3H4N2)2(CH4O)2](ClO4)2 or [Cu2(dmoxpn)(HIm)2(CH3OH)2](ClO4)2, where dmoxpn is the dianion of N,N′‐bis­[3‐(dimethyl­amino)prop­yl]oxamide and HIm is imidazole, consists of a centrosymmetric trans‐oxamidate‐bridged copper(II) binuclear cation, having an inversion centre at the mid‐point of the central C—C bond, and two perchlorate anions. The CuII atom has square‐pyramidal coordination geometry involving two N atoms and an O atom from the dmoxpn ligand, an N atom from an imidazole ring, and an O atom from a methanol mol­ecule. The crystal structure is stabilized by O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds and imidazole π–π stacking inter­actions to form a three‐dimensional supra­molecular array.  相似文献   

14.
The synthesis of a novel series of the intermediates N2(N3)‐[1‐alkyl(aryl/heteroaryl)‐3‐oxo‐4,4,4‐trifluoroalk‐1‐en‐1‐yl]‐2‐aminopyridines [F3CC(O)CH?CR1(2? NH?C5H3N)] and 2,3‐diaminopyridines [F3CC(O)CH?CR1(2‐NH2‐3‐NH? C5H3N)], where R1 = H, Me, C6H5, 4‐FC6H4, 4‐CIC6H4, 4‐BrC6H4, 4‐CH3C6H4, 4‐OCH3C6H4, 4,4′‐biphenyl, 1‐naphthyl, 2‐thienyl, 2‐furyl, is reported. The corresponding series of 2‐aryl(heteroaryl)‐4‐trifluoromethyl‐3H‐pyrido[2,3‐b][1,4]diazepin‐4‐ols obtained from intramolecular cyclization reaction of the respective trifluoroacetyl enamines or from the direct cyclocondensation reaction of 4‐methoxy‐1,1,1‐trifluoroalk‐3‐en‐2‐ones with 2,3‐diaminopyridine, under mild conditions, is also reported.  相似文献   

15.
Methyl 2‐benzamido‐4‐(3,4‐dimethoxyphenyl)‐5‐methylbenzoate, C24H23NO5, (Ia), and N‐{5‐benzoyl‐2‐[(Z)‐2‐methoxyethenyl]‐4‐methylphenyl}benzamide, C24H21NO3, (IIa), were formed via a Diels–Alder reaction of appropriately substituted 2H‐pyran‐2‐ones and methyl propiolate or (Z)‐1‐methoxybut‐1‐en‐3‐yne, respectively. Each of these cycloadditions might yield two different regioisomers, but just one was obtained in each case. In (Ia), an intramolecular N—H...O hydrogen bond closes a six‐membered ring. A chain is formed due to aromatic π–π interactions, and a three‐dimensional framework structure is formed by a combination of C—H...O and C—H...π(arene) hydrogen bonds. Compound (IIa) was formed not only regioselectively but also chemoselectively, with just the triple bond reacting and the double bond remaining unchanged. Compound (IIa) crystallizes as N—H...O hydrogen‐bonded dimers stabilized by aromatic π–π interactions. Dimers of (IIa) are connected into a chain by weak C—H...π(arene) interactions.  相似文献   

16.
The crystal structure of the title complex, [Cu(C7H8N4)2(H2O)2](ClO4)2, consists of a discrete centrosymmetric [Cu(C7H8N4)2(H2O)2]2+ cation and two perchlorate anions. The CuII centre is six‐coordinated by four N donors from the two pyrazole rings [Cu—N 1.998 (2) and 2.032 (3) Å] and two O atoms from the water mol­ecules occupying the apical sites [Cu—O 2.459 (3) Å]. The coordination geometry of the complex can be described as octahedral. There is a unique three‐dimensional network in which the perchlorate units are linked by a combination of strong O—H?O and weak C—H?O hydrogen bonds.  相似文献   

17.
A simple and efficient method for the synthesis of 3‐oxopropanenitriles from variously substituted heterocyclic compounds via direct electrophilic cyanoacetylation is described. A series of heterocyclic 3‐oxopropanenitriles ( 2a , 2b , 2c , 2d , 2e , 2f , 2g , 2h , 2i , 2j , 2k ) have been synthesized using mixed anhydride (acetic or trifluoroacetic anhydride:cyanoacetic acid) in the presence of Mg(ClO4)2·2H2O as catalyst. This method can be extended also for the cyanoacetylation of electron poor aromatic compounds.  相似文献   

18.
The title compound, [Ag2(C7H4ClO2)2(C5H6N2)2], lies about an inversion centre and the Ag atom is three‐coordinated by two O atoms and one N atom from three different ligands. The 4‐chloro­benzoate anion acts as a monodonor ligand, bridging two inversion‐related Ag atoms of the compound into a dimer. There are weak intermolecular N—H⋯O hydrogen bonds in the structure.  相似文献   

19.
Under hydrothermal conditions, the reaction of racemic 3‐pyridyl‐3‐aminopropionic acid (rac‐HPAPA) with Eu(ClO4)3· 6H2O affords a 1‐D chain complex, [Eu(3‐PYA)3(H2O)]n ( 1 ) (3‐PYA=3‐pyridylacrylate), which represents an example of neutral 1‐D coordination polymeric material based on 3‐HPYA (HPYA= pyridylacrylic acid) ligand with strong red fluorescent emission in the solid state.  相似文献   

20.
In the crystal structure of the title complex, [Ni2(C10H20N4O2)(C12H12N2)2](ClO4)2 or [Ni(dmaeoxd)Ni(dmbp)2](ClO4)2 {H2dmaeoxd is N,N′‐bis­[2‐(dimethyl­amino)ethyl]oxamide and dmbp is 4,4′‐dimethyl‐2,2′‐bipyridine}, the deprotonated dmaeoxd2− ligand is in a cis conformation and bridges two NiII atoms, one of which is located in a slightly distorted square‐planar environment, while the other is in an irregular octa­hedral environment. The cation is located on a twofold symmetry axis running through both Ni atoms. The dmaeoxd2− ligands inter­act with each other via C—H⋯O hydrogen bonds and π–π inter­actions, which results in an extended chain along the c axis.  相似文献   

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