Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Dalton Trans ; 2020 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-32073071

RESUMO

The reduction of [(dpp-bian)BBr] (1, dpp-bian = 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene) with dilithium naphthalenide in Et2O gives [{(dpp-bian)BBr}Li2(Et2O)2]2 (3). The treatment of [(dpp-bian)BONa] (5) and [(dpp-bian)Ge:] (7) with sodium is accompanied by protonation of the acenaphthylene fragment and affords [{(H-dpp-bian)BONa(dme)2}Na(dme)3] (6) and [(H-dpp-bian)Ge:][Na(dme)3] (8), respectively. Compounds 3, 6 and 8 have been characterized by 1H NMR and IR spectroscopy. The molecular structures of 3, [(dpp-bian)BOK] (4) and 8 have been established by single crystal X-ray analysis.

2.
Chem Asian J ; 14(17): 2979-2987, 2019 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-31298502

RESUMO

New nickel-based complexes of 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene (dpp-bian) with BF4 - counterion or halide co-ligands were synthesized in THF and MeCN. The nickel(I) complexes were obtained by using two approaches: 1) electrochemical reduction of the corresponding nickel(II) precursors; and 2) a chemical comproportionation reaction. The structural features and redox properties of these complexes were investigated by using single-crystal X-ray diffraction (XRD), cyclic voltammetry (CV), and electron paramagnetic resonance (EPR) and UV/Vis spectroscopy. The influence of temperature and solvent on the structure of the nickel(I) complexes was studied in detail, and an uncommon reversible solvent-induced monomer/dimer transformation was observed. In the case of the fluoride complex, the unpaired electron was found to be localized on the dpp-bian ligand, whereas all of the other nickel complexes contained neutral dpp-bian moieties.

3.
Dalton Trans ; 48(10): 3338-3348, 2019 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-30778457

RESUMO

Complexes of divalent ytterbium (1) and europium (2) with a dianionic o-amidophenolate ligand were prepared by both the direct reduction of 4,6-di-tert-butyl-N-(2,6-diisopropylphenyl)-o-iminobenzoquinone (dpp-IQ) and the salt metathesis reaction of potassium o-amidophenolate with LnI2 (Ln = Yb, Eu). Oxidation of o-amidophenolates 1, 2 with one equivalent of dpp-IQ as well as the salt metathesis reaction of potassium o-iminosemiquinolate with LnI2 afforded ligand mixed-valent o-iminosemiquinonato-amidophenolato complexes of trivalent ytterbium (3) and europium (4). All novel complexes 1-4 were fully characterized, including the solid state structures of 1 and 2 determined by single crystal X-ray diffraction. The magnetic properties of paramagnetic 2-4 were examined.

4.
Chemistry ; 25(15): 3858-3866, 2019 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-30570195

RESUMO

The electrochemical characteristics of 2-mono(2,6-diisopropylphenylimino)acenaphthene-1-one (dpp-mian) have been investigated. One-electron reduction of dpp-mian involves the iminoketone fragment, which is revealed by the EPR spectrum obtained after the electrolysis of the dpp-mian solution in tetrahydrofuran (THF). The reduction of dpp-mian with one equivalent of metallic potassium leads to a similar EPR spectrum. The sodium complex [(dpp-mian)Na(dme)]2 (1) produces an EPR signal with hyperfine coupling on the nitrogen atom of the iminoketone fragment of the dpp-mian ligand. Dpp-mian can also be reduced in a one-electron process by SnCl2 ×(dioxane). In this case, complex (dpp-mian)2 SnCl2 (2) is formed, with the tin atom displaying an oxidation state of +4. Tin(II) chloride dihydrate, SnCl2 ×2(H2 O), also reduces dpp-mian, but the two ligands bound to tin in the product form a new carbon-carbon bond between the ketone moieties of the dpp-mian monoanions to form complex (bis-dpp-mian)HSnCl3 (3). Metallic tin reduces dpp-mian to form the (bis-dpp-mian)2 Sn (4) species. Compounds 1-4 were characterized by X-ray diffraction.

5.
Chem Commun (Camb) ; 54(92): 12950-12953, 2018 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-30383054

RESUMO

Reduction of [(dpp-bian)2-M2+(thf)4] (M = Ca, 1; Yb, 6; dpp-bian = 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene) by alkali metals results in heterometallic, [(dpp-bian)3-M2+K+(thf)2]2 (M = Ca, 2; Yb, 7), [(dpp-bian)4-Ca2+A2+(thf)4]2 (A = Na, 3; Li, 4; K, 5), [(dpp-bian)4-Yb2+K2+(thf)4]2 (8) and [(dpp-bian)24-Yb32+K2+(thf)8] (9). The reduction of [(dpp-bian)TmBr(thf)n] (in situ) affords [(dpp-bian)4-Tm3+Na+(thf)]2 (10).

6.
Inorg Chem ; 57(8): 4301-4309, 2018 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-29561149

RESUMO

The reduction of 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene (dpp-Bian) with an excess of La metal in the presence of iodine (dpp-Bian/I2 = 2/1) in tetrahydrofuran (thf) or dimethoxyethane (dme) affords lanthanum(III) complexes of dpp-Bian dianion: deep blue [(dpp-Bian)2-LaI(thf)2]2 (1, 84%) was isolated by crystallization of the product from hexane, while deep green [(dpp-Bian)LaI(dme)2] (2, 93%) precipitated from the reaction mixture in the course of its synthesis. A treatment of complex 1 with 0.5 equiv of I2 in thf leads to the oxidation of the dpp-Bian dianion to the radical anion and results in the complex [(dpp-Bian)1-LaI2(thf)3] (3). Addition of 18-crown-6 to the mixture of 1 and NaCp* (Cp* = 1,2,3,4,5-pentamethylcyclopentadienyl) in thf affords ionic complex [(dpp-Bian)2-La(Cp*)I][Na(18-crown-6)(thf)2] (4, 71%). In the absence of crown ether the alkali metal salt-free complex [(dpp-Bian)2-LaCp*(thf)] (5, 67%) was isolated from toluene. Reduction of complex 1 with an excess of potassium produces lanthanum-potassium salt of the dpp-Bian tetra-anion {[(dpp-Bian)4-La(thf)][K(thf)3]}2 (6, 68%). Diamagnetic compounds 1, 2, 4, 5, and 6 were characterized by NMR spectroscopy, while paramagnetic complex 3 was characterized by the electron spin resonance spectroscopy. Molecular structures of 2-6 were established by single-crystal X-ray analysis.

7.
Dalton Trans ; 42(22): 7952-61, 2013 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-23435476

RESUMO

Boron complexes (dpp-bian)BCl2 (1) and (dpp-bian)BX (X = Cl, 2; Br, 3) (dpp-bian = 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene) have been prepared by reacting mixtures dpp-bian-BX3 (1 : 1) with one (1) and two (2 and 3) equivalents of sodium correspondingly in toluene. Complexes 2 and 3 reveal a moderate stability against ambient oxygen and moisture. The reaction of complex 2 with PhC≡CLi gave compound (dpp-bian)B-C≡CPh (4). Treatment of 2 with potassium hydroxide afforded complexes (dpp-bian)B-OH (5) and (dpp-bian)B-OK (6). Boron amide (dpp-bian)B-NH2 (7) has been isolated from the reaction of compound 1 with sodium in liquid ammonia. Borane (dpp-bian)B-H (8) can be prepared by the reactions of complexes 2 and 3 with LiAlH4. Diamagnetic compounds 2-8 have been characterized by IR, (1)H and (11)B NMR spectroscopy; paramagnetic complex 1 has been studied by the ESR method. Molecular structures of 2, 5, 7 and 8 have been determined by X-ray crystallography.

8.
Chemistry ; 18(36): 11264-76, 2012 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-22847958

RESUMO

The treatment of 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene (dpp-bian) with one equivalent of AlCl(3) and three equivalents of sodium in toluene at 110 °C produced a stable dialane, (dpp-bian)Al-Al(dpp-bian) (1). The reaction of compound 1 with pyridine gave Lewis-acid-base adduct (dpp-bian)(Py)Al-Al(Py)(dpp-bian) (2). Acetylene and phenylacetylene reacted with compound 1 to give cycloaddition products [dpp-bian(R(1)R(2))]Al-Al[(R(2)R(1))dpp-bian] (3: R(1)=R(2)=CH; 4: R(1)=CH, R(2)=CPh). These addition reactions occur across Al-N-C moieties and result in the formation of new C-C and C-Al bonds. At elevated temperatures, compound 4 rearranges into complex 5, which consists of a radical-anionic dpp-bian ligand and two bridging alken-1,2-diyl moieties, (dpp-bian)Al(HCCPh)(2)Al(dpp-bian). This transformation is accompanied by cleavage of the dpp-bian-ligand-alkyne C-C bond, as well as of the Al-Al bond. In contrast to its analogous gallium complex, compound 1 is reactive towards internal alkynes. In the reaction of compound 1 with PhC≡CMe, besides symmetrical addition product [dpp-bian(R(1)R(2))]Al-Al[(R(2)R(1))dpp-bian] (R(1)=CMe, R(2)=CPh; 6), monoadduct [dpp-bian(R(1)R(2))]Al-Al(dpp-bian) (R(1)=CMe, R(2)=CPh; 7) was also isolated. Complexes 1-7 were characterized by IR, (1)H NMR (1-4), and electronic absorption spectroscopy (3-5); the molecular structures of compounds 1-7 were determined by single-crystal X-ray diffraction.


Assuntos
Acenaftenos/química , Alquinos/química , Alumínio/química , Amidas/química , Compostos Organometálicos/química , Cristalografia por Raios X , Ligantes , Modelos Moleculares , Estrutura Molecular , Compostos Organometálicos/síntese química , Oxirredução , Teoria Quântica
9.
Chemistry ; 16(25): 7563-71, 2010 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-20486109

RESUMO

The reduction of digallane [(dpp-bian)Ga-Ga(dpp-bian)] (1) (dpp-bian=1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene) with lithium and sodium in diethyl ether, or with potassium in THF affords compounds featuring the direct alkali metal-gallium bonds, [(dpp-bian)Ga-Li(Et(2)O)(3)] (2), [(dpp-bian)Ga-Na(Et(2)O)(3)] (3), and [(dpp-bian)Ga-K(thf)(5)] (7), respectively. Crystallization of 3 from DME produces compound [(dpp-bian)Ga-Na(dme)(2)] (4). Dissolution of 3 in THF and subsequent crystallization from diethyl ether gives [(dpp-bian)Ga-Na(thf)(3)(Et(2)O)] (5). Ionic [(dpp-bian)Ga](-)[Na([18]crown-6)(thf)(2)](+) (6a) and [(dpp-bian)Ga](-)[Na(Ph(3)PO)(3)(thf)](+) (6b) were obtained from THF after treatment of 3 with [18]crown-6 and Ph(3)PO, respectively. The reduction of 1 with Group 2 metals in THF affords [(dpp-bian)Ga](2)M(thf)(n) (M=Mg (8), n=3; M=Ca (9), Sr (10), n=4; M=Ba (11), n=5). The molecular structures of 4-7 and 11 have been determined by X-ray crystallography. The Ga-Na bond lengths in 3-5 vary notably depending on the coordination environment of the sodium atom.

10.
Dalton Trans ; (24): 4689-94, 2009 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-19513477

RESUMO

Molybdenum hexacarbonyl reacts with 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene (, dpp-BIAN) and 1,2-bis[(trimethylsilyl)imino]acenaphthene (, tms-BIAN) in toluene to produce (dpp-BIAN)Mo(CO)(4) () and (tms-BIAN)Mo(CO)(4) (), respectively. The reaction of [CpNi(CO)](2) with yields (dpp-BIAN)NiCp (). Metathesis between Li(2)(tms-BIAN) and NiCl(2)(dppe) affords the Ni(0) complex (tms-BIAN)Ni(dppe) (). The diamagnetic compounds , and have been characterized by (1)H, (29)Si and (31)P NMR spectroscopy, IR spectroscopy and elemental analysis. The ESR spectrum of the paramagnetic compound indicates the presence of Ni(i) coordinated by Cp and a neutral dpp-BIAN ligand. The molecular structures of have been determined by single-crystal X-ray analysis.

12.
Chemistry ; 13(25): 7050-6, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17696191

RESUMO

1,2-Bis[(2,6-diisopropylphenyl)imino]acenaphthene) (dpp-bian) stabilizes gallium-gallium and zinc-gallium bonds (compounds 1-3). The compound [(dpp-bian)Ga-Ga(dpp-bian)] (2) was prepared by the reaction of GaCl3 with K3[dpp-bian] and the heterometallic [(dpp-bian)Zn-Ga(dpp-bian)] (3) was prepared by a simple one-pot reaction of [{(dpp-bian)ZnI}(2)] with GaCl3 and K4[dpp-bian]. In contrast to [(dpp-bian)Zn-Zn(dpp-bian)] (1) and 3, compound 2 is ESR silent, thus proving the dianionic character of both dpp-bian ligands. The solution ESR spectrum of 3 reveals the coupling of an unpaired electron with the gallium nuclei (69)Ga and (71)Ga (A((69)Ga)=0.97, A((71)Ga)=1.23 mT), thus confirming the presence of Zn-Ga bonds in solution. According to the results of the X-ray crystal structure analyses the metal-metal bond lengths in 2 (2.3598(3) A) and 3 (2.3531(8) A) are close to that found in 1 (2.3321(2) A). The electronic structures of compounds 2 and 3 were studied by DFT (B3 LYP/6-31G* level). The metal-metal pi bond in 2 is mainly formed by overlap of the p orbitals of Ga in the HOMO and HOMO-1, the latter showing a stronger interaction. The s and p orbitals of Ga overlap in the deeper located HOMO-17 producing a Ga-Ga sigma bond. In contrast to the Zn-Zn bond in 1, which has 95 % s character, the NBO (natural bond order) analysis of 2 reveals 67.8 % s, 32.0 % p, and 0.2 % d character for the Ga-Ga bond. Compound 3 has a doublet electronic ground state. The unpaired electron occupies the alpha HOMO-1 localized at the Zn-containing fragment. The Ga-Zn bond is mainly formed by overlap of the metal orbitals in the alpha HOMO-6 and beta HOMO-5. According to the results of the NBO analysis, the Zn wave functions are responsible for 28.7 % of the Zn-Ga bond, with 96.7 % s, 1.0 % p, and 2.3 % d character.

13.
Chemistry ; 13(15): 4216-22, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17440904

RESUMO

The reactions of the disodium salt of the 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene (dpp-BIAN) ligand with one equivalent of Me2AlCl in diethyl ether, toluene, and benzene produced the complexes [Na(Et2O)2(dpp-BIAN)AlMe2] (1), [Na(eta6-C7H8)(dpp-BIAN)AlMe2] (2) and [Na(eta6-C6H6)(dpp-BIAN)AlMe2] (3), respectively. Recrystallization of 1 from hexane afforded solvent-free [{Na(dpp-BIAN)AlMe2}n] (4) or [Na(Et2O)(dpp-BIAN)AlMe2] (5) depending on the temperature of the solvent. The molecular structures of 1-5 have been determined by single-crystal X-ray diffraction. The sodium cation coordinates either one of the naphthalene rings (1) or the diimine part of the dpp-BIAN ligand (2-5). In the complexes 2 and 3, the sodium cation additionally coordinates the toluene (2) or benzene molecule (3) in an eta6-fashion.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA