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22 results on '"A, Ardizzoia"'

1. Oxidative addition of N-H bonds to a metal center: synthesis, characterization, and crystal structure of new rhodium(III) hydrido-pyrazolate complexes

Author

Ardizzoia, G. Attilio, Brenna, Stefano, LaMonica, Girolamo, Maspero, Angelo, Masciocchi, Norberto, and Moret, Massimo

Subjects
Chemistry, Inorganic -- Research, Rhodium -- Physiological aspects, Hydrogen bonding -- Physiological aspects, Coordination compounds -- Physiological aspects, Oxidation-reduction reaction -- Physiological aspects, Nitrogen -- Physiological aspects, Chemistry
Abstract

Research has been conducted on the oxidative addition of the N-H bonds to pyrazole and related molecules. Results demonstrate the formation of bishydridorhodium(III) species.

Published
2002

2. Metal imidazolato complexes: synthesis, characterization, and X-ray powder diffraction studies of group 10 coordination polymers

Author

Masciocchi, Norberto, Ardizzoia, G. Attilio, LaMonica, Girolamo, Maspero, Angelo, Galli, Simona, and Sironi, Angelo

Subjects
Chemistry, Inorganic -- Research, Coordination compounds -- Physiological aspects, Imidazole -- Physiological aspects, Diffraction -- Analysis, Polymers -- Physiological aspects, Chemistry
Abstract

Research has been conducted on the binary metal imidazolates of the group 10 metals. The preparation of these compounds has been carried out and the results indicate that these compounds are amorphous.

Published
2001

3. Metal pyrazolato complexes. Synthesis, characterization, and X-ray powder diffraction studies of group 12 coordination polymers

Author

Masciocchi, Norberto, Ardizzoia, G. Attilio, Maspero, Angelo, LaMonica, Girolamo, and Sironi, Angelo

Subjects
Polymers -- Research, Coordination compounds -- Research, Chemistry
Abstract

The preparation and characterization of a number of polymeric pyrazolato complexes through thermal analyses and X-ray powder diffraction methods were conducted. Ab initio X-ray powder diffraction methods revealed that the isomorphous (Zn(pz)2)n and (Cd(pz)2)n species were 1-D polymers having tetrahedrally coordinated metals. Results have demonstrated the possibility of fully characterizing a number of elusive polymeric species using coupling selective synthetic approaches with spectroscopic, thermal and powder diffraction analyses.

Published
1999

4. Syntheses, structures, and reactivity of polynuclear pyrazolato copper(I) complexes, including an ab-initio XRPD study of (Cu(dmnpz))3 (Hdmnpz = 3,5-dimethyl-4-nitropyrazole)

Author

Ardizzoia, G. Attilio, Cenini, Sergio, La Monica, Girolamo, Masciocchi, Norberto, Maspero, Angelo, and Moret, Massimo

Subjects
Copper compounds -- Research, Polycyclic compounds -- Research, Reactivity (Chemistry) -- Research, Inorganic compounds -- Synthesis, Chemistry
Abstract

Two new homoleptic copper(I) pyrazolate complexes, the trinuclear (Cu(dmnpz))3 and the tetranuclear anionic (Cu4(dmanpz)6)2- species were synthesized and their structures determined. An examination of their reactivity showed that both complexes readily react with cyclohexyl isocyanide, giving the dinuclear complexes (Cu(dmnpz)(RNC))2 and (Cu(dmnpz)(RNC)2)2, and with PPh3 to afford the dimeric derivative (Cu(dmnpz)(OOh3))2.

Published
1998

5. Silver(I) pyrazolates: synthesis and X-ray and 31P-NMR characterization of triphenylphosphine complexes and their reactivity toward heterocumulenes

Author

Ardizzoia, G. Attilio, Monica, Girolamo La, Maspero, Angelo, Moret, Massimo, and Masciocchi, Norberto

Subjects
Coordination compounds -- Analysis, Silver compounds -- Analysis, Gold compounds -- Analysis, Chemistry
Abstract

Silver(I) pyrazolate was reacted with triphenylphosphine to form a series of dinuclear [Ag2(pz)2(PPh3)2] and [Ag2(pz)2(PPh3)3 complexes. Both compounds readily reacted with heterocumulenes such as CS2, COS, CO2 and RNCO to produce functionalized pyrazolates. Analysis of [Ag(pz-CS2)(PPh3)2] also via nuclear magnetic resonance spectroscopy also indicated the presence of S,S coordination in the pyrazolecarbodithiolate fragment of the complex.

Published
1997

6. Polymorphism in coordination chemistry: selective syntheses and ab initio X-ray powder diffraction characterization of two new crystalline phases of solid [Pd(dmpz)2(Hdmpz)2]2 (Hdmpz = 3,5-dimethylpyrazole)

Author

Masciocchi, Norberto, Ardizzoia, G. Attilio, Monica, Girolamo La, Moret, Massimo, and Sironi, Angelo

Subjects
Pyrazoles -- Analysis, Polymorphism (Crystallography) -- Analysis, Chirality -- Analysis, Chemistry
Abstract

The reaction of alpha-[Pd(dmpz)2(Hdmpz)2]2 with COS led to the formation of the [Pd(dmpz)2(Hdmpz)2]2.COS intermediate which reacts with -COS to form beta-[Pd(dmpz)2(Hdmpz)2]2. Analysis of the X-ray diffraction data of the alpha, gamma and beta polymorphs of [Pd(dmpz)2(Hdmpz)2]2 indicate the presence of similar molecules that are not tautomers or conformational isomers. Furthermore, the identity of the [Pd(dmpz)2(Hdmpz)2]2 molecules were not altered in the beta and gamma phases.

Published
1997

7. Synthesis, X-ray structure, and catalytic properties of the unprecedented tetranuclear copper(I) species (Cu(dppz))(sub 4) (Hdppz = 3, 5-diphenylpyrazole)

Author

Ardizzoia, G. Attilio, Cenini, Sergio, Monica, Girolamo La, Masciocchi, Norberto, and Moret, Massimo

Subjects
Copper compounds -- Research, Catalysts -- Analysis, X-ray crystallography -- Analysis, Chemistry
Abstract

A novel copper(I) complex, (Cu(dppz))4, is actively involved in the catalytic oxidative reaction between primary aromatic amines and the respective azobenzenes when molecular oxygen is available. Spectroscopic and chemical studies suggest the existence of transition copper(II) imido species. The tetrameric (Cu(dppz))4 molecule has D2 symmetry with the dppz ligands supporting the Cu...Cu interactions.

Published
1994

8. Synthesis of (Cu dcmpz)n and its reactions with carbon monoxide and cyclohexyl isocyanide. Crystal structures of Cu2(dcmpz)2(py)2(CO) and (Cu dcmpz RNC)2 (Hdcmpz = 3,5-dicarbomethoxypyrazole, R = cyclohexyl)

Author

Ardizzoia, G. Attilio, Beccalli, Egle M., La Monica, Girolamo, Masciocchi, Norberto, and Moret, Massimo

Subjects
Copper compounds -- Research, Coordination compounds -- Research, Crystal lattices -- Research, Chemistry
Abstract

The reaction of 3, 5-dicarbomethoxypyrazole (Hdcmpz) with Cu(CH3CN)4(BF)4 results in the complex (Cu dcmpz)n. The reaction of (Cu dcmpz)n with cyclohexyl isocyanide produces the dimeric complex (Cu dcmpz RNC)2 which is composed of a binuclear complex of Cu(I) bridged by two dcmpz ligands and to two RNC (R = cyclohexyl) groups. Meanwhile, carbonylation of (Cu dcmpz)n in pyridine results in the dinuclear Cu(I) derivative Cu2(dcmpz)2(py)2(CO). The derivative consists of a discrete binuclear complex of Cu(I) bridged by two dcmpz ligands and joined to two pyridine and one carbonyl group.

Published
1992

9. Reversible depolymerization of silver pyrimidinolate into cyclic hexamers

Author

Masciocchi, Norberto, Corradi, Eleanora, Moret, Massimo, Ardizzoia, Attilio, Maspero, Angelo, La Monica, Girolamo, and Sironi, Angelo

Subjects
Silver compounds -- Research, Ring-opening polymerization -- Research, Chemistry
Abstract

The solid state transformation of [Ag(pyrimidinolate)]n*2nH2O is thermally induced and occurs in two separate steps. The first step is the dehydration with amorphization and the second one is devitrification. Together, the two processes form a cyclic silver pyrimidinolate oligomer. The transformation is reversible and is an example of a rare form of ring-opening polymerization in a coordination compound.

Published
1997

10. Oxidative Addition of N−H Bonds to a Metal Center: Synthesis, Characterization, and Crystal Structure of New Rhodium(III) Hydrido−Pyrazolate Complexes

Author

Stefano Brenna, G. Lamonica, Gian Attilio Ardizzoia, Massimo Moret, Norberto Masciocchi, Angelo Maspero, Ardizzoia, G, Brenna, S, Lamonica, G, Maspero, A, Masciocchi, N, and Moret, M

Subjects
CHIM/03 - CHIMICA GENERALE E INORGANICA, Stereochemistry, Oxidative addition, chemistry.chemical_element, pyrazolate, Crystal structure, rhodium(III), Rhodium, Inorganic Chemistry, Metal, chemistry, visual_art, Polymer chemistry, visual_art.visual_art_medium, Physical and Theoretical Chemistry
Abstract

A number of pyrazoles easily react with [Rh(PPh3)(4)H], leading to hydrido-pyrazolate complexes through oxidative addition of N-H bonds to the metal center. The reaction products have been characterized by IR and multinuclear NMR spectroscopy and standard X-ray diffraction methods.

Published
2002
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11. Synthesis, X-ray Structure, and Catalytic Properties of the Unprecedented Tetranuclear Copper(I) Species [Cu(dppz)]4 (Hdppz = 3,4-Diphenylpyrazole)

Author

Norberto Masciocchi, Gian Attilio Ardizzoia, G. Lamonica, Massimo Moret, and Sergio Cenini

Subjects
Tetrafluoroborate, Stereochemistry, Isocyanide, chemistry.chemical_element, Ether, Crystal structure, Triclinic crystal system, Copper, Inorganic Chemistry, chemistry.chemical_compound, Crystallography, chemistry, X-ray crystallography, Physical and Theoretical Chemistry, Triethylamine
Abstract

The reaction of [Cu(CH 3 CN) 4 ](BF 4 ) with 3,5-diphenylpyrazole (Hdppz) in the presence of triethylamine yields quantitatively the new copper(I) complex [Cu(dpp)] 4 (1). Reaction of 1 with stoichiometric amounts of cyclohexyl isocyanide (RNC) indiethyl ether affords the dimeric complex [Cu(dppz)(RNC)] 2 (2). For both complexes 1 and 2 an X-ray crystal structure analysis has been performed. Crystals of 1 are triclinic, space group P1 (No. 2), with a=19.423(9) A, b=11.627(1) A, c=11.905(2) A, α=85.75(1) o , β=72.92(2) o , γ=88.92(2) o , and Z=2

Published
1994
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12. Reaction of dioxygen with poly[(3,5-dimethylpyrazolato)copper]. Crystal structure, reactivity, and catalytic properties of [Cu8(dmpz)8(OH)8]

Author

F. Cariati, Massimo Moret, M. Angaroni, Norberto Masciocchi, Gian Attilio Ardizzoia, G. Lamonica, and Sergio Cenini

Subjects
Inorganic Chemistry, Crystallography, Hydrogen, Chemistry, Stereochemistry, X-ray crystallography, chemistry.chemical_element, Molecule, Reactivity (chemistry), Crystal structure, Physical and Theoretical Chemistry, Oxygen, Catalysis
Published
1991
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13. Silver(I) Pyrazolates. Synthesis and X-ray and (31)P-NMR Characterization of Triphenylphosphine Complexes and Their Reactivity toward Heterocumulenes

Author

G. Attilio Ardizzoia, Norberto Masciocchi, Angelo Maspero, Girolamo La Monica, Massimo Moret, Ardizzoia, G, Lamonica, G, Maspero, A, Moret, M, and Masciocchi, N

Subjects
COORDINATION, Chemistry, Ligand, Stereochemistry, 3,5ME2-PZ = 3,5-DIMETHYLPYRAZOLATE, COPPER(I), Crystal structure, Triclinic crystal system, Pyrazole, Ring (chemistry), Inorganic Chemistry, Crystallography, chemistry.chemical_compound, CATALYTIC PROPERTIES, Molecule, CRYSTAL-STRUCTURE, Reactivity (chemistry), COS, LIGAND, Physical and Theoretical Chemistry, Triphenylphosphine, CARBONYL SULFIDE, CU(3,5ME2-PZ-C(S)-S)(CNR)2, MOLECULAR-STRUCTURE
Abstract

Silver(I) pyrazolate was reacted with triphenylphosphine, leading to the dinuclear [Ag-2(pz)(2)(PPh3)(2)] and [Ag-2(pz)(2) (PPh3)(3)] complexes (Hpz = pyrazole), which were extensively characterized by P-31-NMR methods and single-crystal X-ray analyses. Crystals of [Ag-2(pz)(2)(PPh3)(2)] are triclinic, space group P (1) over bar, with a = 9.567(2) Angstrom, b = 11.440(2) Angstrom, c = 10.073(2) Angstrom, alpha = 93.59(2)degrees, beta = 64.01(2)degrees, gamma = 107.24(2)degrees, Z = 1, and D-calc = 1.539 g.cm(-3); final R = 0.028 for 2532 independent reflections having F > 4 sigma(F). They contain centrosymmetric dimers with trigonally coordinated silver atoms, which are 3.870(1)Angstrom apart. Crystals of [Ag-2(pz)(2) (PPh3)(3)] are triclinic, space group P (1) over bar, with a = 9.752(2) Angstrom, b = 14.163(2) Angstrom, c = 20.450(2) Angstrom, alpha = 101.84(1)degrees, beta = 99.83(2)degrees, gamma = 100.68(2)degrees, Z = 2, and D-calc = 1.424 g.cm(-3); final R = 0.025 for 7075 independent reflections having F > 4 sigma(F). Each molecule contains two inequivalent silver ions, bearing one and two phosphines, respectively, and a Ag(mu-pz)(2)Ag ring with a rare twisted conformation. Both complexes readily react with heterocumulenes such as CS2, COS, CO2, and RNCO, affording new derivatives, the nature of which is dependent on the experimental conditions. Single-crystal X-ray analysis of [Ag(pz-CS2)(PPh3)(2)] has shown the unexpected S,S coordination of the pyrazolecarbodithioate fragment. Its crystals are triclinic, space group P (1) over bar, with a 10.329(4) Angstrom, b = 13.082(2) Angstrom, c = 14.284(3) Angstrom, alpha = 86.71(2)degrees, beta = 75.14(2)degrees, gamma = 74.79(2)degrees, Z = 2, and D-calc = 1.431 g.cm(-3); final R = 0.028 for 5179 independent reflections having F > 4 sigma(F).

Published
1997

14. One-dimensional polymers containing strictly collinear metal ions: synthesis and XRPD characterization of homoleptic binary metal pyrazolates

Author

G. Attilio Ardizzoia, Stefano Brenna, Angelo Sironi, G. Lamonica, Norberto Masciocchi, Simona Galli, and Angelo Maspero

Subjects
Stereochemistry, Chemistry, Inorganic Chemistry, Metal, Crystal, Crystallography, chemistry.chemical_compound, Transition metal, Intramolecular force, visual_art, visual_art.visual_art_medium, Orthorhombic crystal system, Physical and Theoretical Chemistry, Homoleptic, Powder diffraction, Monoclinic crystal system
Abstract

The synthesis of a number of 3d transition metal binary pyrazolates in microcrystalline form, thus suitable for a full XRPD characterization, has been pursued. The crystal and molecular structures of the Fe(pz)3, Co(pz)2, Co(pz)3, and Ni(pz)2 polymers, together with the few congeners reported in the recent literature, show that these species tend to afford highly crystalline materials where strictly collinear chains of metal atoms are present. Depending on the synthetic strategy used, Ni(pz)2 has been found to crystallize as two different alpha (orthorhombic) and beta (monoclinic) phases, possessing nearly identical intramolecular features. Data for each compound follow. Fe(pz)3: C9H9FeN6, hexagonal, P63/m, a = 9.1745(3) A, c = 7.2191(4) A, Z = 2. Co(pz)2: C6H6CoN4, orthorhombic, Ibam, a = 7.5239(5) A, b = 14.3461(9) A, c = 7.4331(5) A, Z = 4. Co(pz)3: C9H9CoN6, hexagonal, P63/m, a = 9.1966(3) A, c = 7.1051(3) A, Z = 2. Alpha-Ni(pz)2: C6H6N4Ni, orthorhombic, Cmcm, a = 16.6758(11) A, b = 6.4872(4) A, c = 6.9423(6) A, Z = 4. Beta-Ni(pz)2: C6H6N4Ni, monoclinic, P21/m, a = 9.967(2) A, b = 6.975(1) A, c = 6.016(1), A, beta = 98.50(1)degrees, Z = 2. The thermal stability and the detailed structural properties of these model compounds have been evaluated, in the light of the technologically relevant crystal phases (the well-known metal-diazolates showing reversible spin-crossover or spin-transition behavior) obtainable upon doping, magnetic dilution, and ring substitution (in the 4-position).

Published
2002

15. Metal Pyrazolato Complexes. Synthesis, Characterization, and X-ray Powder Diffraction Studies of Group 12 Coordination Polymers

Author

Norberto Masciocchi, G. Attilio Ardizzoia, Angelo Maspero, Girolamo LaMonica, and Angelo Sironi

Subjects
Inorganic Chemistry, Physical and Theoretical Chemistry
Abstract

A number of polymeric pyrazolato complexes have been prepared and characterized by spectroscopy, thermal analyses (DSC and TGA), and X-ray powder diffraction (XRPD) methods. Ab initio XRPD studies showed that the (isomorphous) [Zn(pz)(2)](n)() and [Cd(pz)(2)](n)() species (Hpz = pyrazole) are 1-D polymers containing tetrahedrally coordinated metals and M(mgr;-pz)(2)M (M = Zn, Cd) bridges, much alike [Cu(pz)(2)](n)() [orthorhombic, Ibam, a = 7.4829(4), b = 14.3844(6), c = 7.3831(3) Å (Zn) and a = 7.8591(6), b = 13.652(1), c = 7.9165(4) Å (Cd)]; differently, Hg(pz)(2) [triclinic, Ponemacr;, a = 7.4097(3), b = 9.4474(3), c = 5.8345(3) Å, alpha = 96.310(2), beta = 96.752(3), and gamma = 73.694(2) degrees ] is best described as a mononuclear complex, containing two monodentate pyrazolato ligands loosely interacting, through long(er) Hg.N contacts with neighboring molecules. During the synthesis of the latter, an intermediate phase was obtained, and characterized as Hg(pz)NO(3), which contains a polymeric polycation, [Hg(pz)](n)()(n)()(+), based on Hg(mgr;-pz)Hg bridges, and uncoordinated NO(3)(-) groups (orthorhombic, Pcmn, a = 17.2985(9), b = 5.2538(3), c = 7.3912(4) Å). All structures were ultimately refined by the Rietveld method.

Published
2001

21. Isolation of ionic products in the reaction of carbon dioxide with (tetrahydroborato)copper(I) complexes: synthesis and reactions of [(biL)(Ph3P)2Cu][HB(O2CH)3] and [(biL)(Ph3P)2Cu][H2B(O2CH)2] (biL = 1,10-phenanthroline, 3,4,7,8-tetramethyl-1,10-phenanthroline)

Author

F. Cariati, Maddalena Pizzotti, G. La Monica, Gian Attilio Ardizzoia, and Sergio Cenini

Subjects
Phenanthroline, Inorganic chemistry, Ionic bonding, chemistry.chemical_element, Nuclear magnetic resonance spectroscopy, Medicinal chemistry, Copper, Inorganic Chemistry, chemistry.chemical_compound, chemistry, Carbon dioxide, Reactivity (chemistry), Carboxylate, Physical and Theoretical Chemistry, Triphenylphosphine
Published
1985
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