Sodium cation migration above the diimine pi-system of solvent coordinated dpp-BIAN sodium aluminum complexes (dpp-BIAN=1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene)

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.     

1,3,2-Diazasilols based on 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene

Reduction of 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene (1, dpp-bian) in the presence of SiCl₄ with two equivalents of potassium graphite (KC₈) in tetrahydrofuran leads to the formation of compound (dpp-bian)SiCl₂ (2), which was also synthesized by the exchange reaction of SiCl₄ with the magnesium complex (dpp-bian)Mg(THF)₃. An analog of compound 2, the bromo derivative (dpp-bian)SiBr₂ (3), was obtained by the reaction of SiBr4 with one equivalent of Na2(dpp-bian) (in situ from Na and dpp-bian) in toluene. The silylene (dpp-bian)Si (4) was synthesized by the reduction of a mixture of dpp-bian and SiCl₄ (1: 1) with four equivalents of potassium graphite in tetrahydrofuran. Treatment of compound 4 with diimine 1 gives the derivative (dpp-bian)₂Si (5). Compounds 2–5 were characterized by ¹H, ¹³C, and ²⁹Si NMR spectroscopy, as well as by elemental analysis, their molecular structure was established by X-ray diffraction studies.     

Stannylenes based on neutral,anionic, and dianionic 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene

Russian Chemical Bulletin - The reaction of 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene (dpp-bian (1)) with one equivalent of SnCl2 gave the complex [(dpp-bian)0SnCl2] (2) containing the...     

Magnesium and calcium complexes with two diimine radical-anion ligands. Molecular structure of the Ca complex with 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene

Four- and five-coordinate magnesium and calcium complexes containing two diimine radical-anion ligands with compositions (dpp-BIAN)₂Mg (1), (dpp-BIAN)₂Ca (2), (dtb-BIAN)₂Mg (3), and (dtb-BIAN)₂Ca(THF) (4) (dpp-BIAN is 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene and dtb-BIAN is 1,2-bis[(2,5-di-tert-butylphenyl)imino]acenaphthene) were synthesized. At 120 K, the ESR spectra of complexes 1–4 in a toluene matrix show signals characteristic of biradical derivatives. The molecular structure of compound 2 was established by X-ray diffraction analysis. At 293 K, the magnetic moments of compounds 1, 2, 3, and 4 are 2.55, 2.57, 2.76, and 2.79 μ_B, respectively, which are indicative of the presence of two unpaired electrons localized on the ligands.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2051–2055, October, 2004.     

Addition of phenylacetylene and camphor to the complex [(dpp-bian)Eu(dme)<Subscript>2</Subscript>] (dpp-bian is the 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene dianion)

The reduction of 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene (dpp-bian) with an excess of europium metal in 1,2-dimethoxyethane (dme) produces a divalent europium complex with the dpp-bian dianion, [(dpp-bian)Eu(dme)₂] (1). The reactions of 1 with phenyl-acetylene and camphor proceed via protonation of the diimine ligand to form the monomeric amido-amino complexes of divalent europium — [H(dpp-bian)Eu(C≡CPh)(dme)₂] (2) and [H(dpp-bian)Eu(camphor)(dme)₂] (3), respectively. Compounds 2 and 3 were characterized by IR spectroscopy and elemental analysis. Their molecular structures were determined by X-ray diffraction. Compounds 2 and 3 were shown to be monomeric seven-coordinate europium(ii) complexes with terminal phenylethynyl and enol ligands, respectively. According to the IR spectroscopic data, the terminal ligands in complexes 2 and 3 undergo tautomerization involving backward proton transfer from the amido-amino ligand to the substrate. The magnetic moment of compound 2 (8.03 μB) remains constant in the temperature range of 4—300 К and confirms the presence of divalent europium.     

Mononuclear gallium complexes with the redox-active dmp-bian ligand (dmp-bian is 1,2-bis[(2,6-dimethylphenyl)imino]acenaphthene): synthesis and reactions with alkynes

Russian Chemical Bulletin - The direct reduction of 1,2-bis[(2,6-dimethylphenyl)imino]acenaphthene (dmp-bian (1)) with gallium metal in toluene affords the solvent-free bis-ligand complex...     

Synthesis and Structural Studies of Group 2B Transition Metal Complexes with the Bulky Nitrogen Ligand Bis[ N-(2,6-diisopropylphenyl) imino]acenaphthene

Group 2B transition metal complexes of bis[N-(2,6-diisopropylphenyl)imino]acenaphthene (o,o-iPr₂C₆H₃-BIAN), namely, [Hg(o,o-iPr₂C₆H₃-BIAN)Cl₂] (1), [Zn(o,o-iPr₂C₆H₃-BIAN)₂](ClO₄)₂ (2), and [Cd(o,o-iPr₂C₆H₃-BIAN)₂](ClO₄)₂ (3) have been synthesized and characterized. In complexes 2 and 3, IR, NMR, and conductivity measurements confirm the coordination of two (o,o-iPr₂C₆H₃-BIAN) ligands to the metal center with two discrete perchlorate anions. X-Ray crystal structure of 1 indicates a distorted tetrahedral geometry with two nitrogen atoms from (o,o-iPr₂C₆H₃-BIAN) ligand and two chloride atoms coordinating to the Hg(II) center.     

2,4,6-Tris(2-pyridyl)-1,3,5-triazine (tptz)-derived [Ru(II)(tptz)(acac)(CH3CN)]+ and mixed-valent [(acac)2Ru(III){(mu-tptz-H+)-}Ru(II)(acac)(CH3CN)]+

Mononuclear [Ru(II)(tptz)(acac)(CH3CN)]ClO4 ([1]ClO4) and mixed-valent dinuclear [(acac)2Ru(III){(mu-tptz-Eta+)-}Ru(II)(acac)(CH3CN)]ClO4 ([5]ClO4; acac = acetylacetonate) complexes have been synthesized via the reactions of Ru(II)(acac)2(CH3CN)2 and 2,4,6-tris(2-pyridyl)-1,3,5-triazine (tptz), in 1:1 and 2:1 molar ratios, respectively. In [1]ClO4, tptz binds with the Ru(II) ion in a tridentate N,N,N mode (motif A), whereas in [5]ClO4, tptz bridges the metal ions unsymmetrically via the tridentate neutral N,N,N mode with the Ru(II) center and cyclometalated N,C- state with the Ru(III) site (motif F). The activation of the coordinated nitrile function in [1]ClO4 and [5]ClO4 in the presence of ethanol and alkylamine leads to the formation of iminoester ([2]ClO4 and [7]ClO4) and amidine ([4]ClO4) derivatives, respectively. Crystal structure analysis of [2]ClO4 reveals the formation of a beautiful eight-membered water cluster having a chair conformation. The cluster is H-bonded to the pendant pyridyl ring N of tptz and also with the O atom of the perchlorate ion, which, in turn, makes short (C-H- - - - -O) contacts with the neighboring molecule, leading to a H-bonding network. The redox potentials corresponding to the Ru(II) state in both the mononuclear {[(acac)(tptz)Ru(II)-NC-CH3]ClO4 ([1]ClO4) > [(acac)(tptz)Ru(II)-NH=C(CH3)-OC2H5]ClO4 ([2]ClO4) > [(acac)(tptz)Ru(II)-NH2-C6H4(CH3)]ClO4 ([3]ClO4) > [(acac)(tptz)Ru(II)-NH=C(CH3)-NHC2H5]ClO4 ([4]ClO4)} and dinuclear {[(acac)2Ru(III){(mu-tptz-H+)-}Ru(II)(acac)(NC-CH3)]ClO4 ([5]ClO4), [(acac)2Ru(III){(mu-tptz-H+(N+-O-)2)-}Ru(II)(acac)(NC-CH3)]ClO4 ([6]ClO4), [(acac)2Ru(III){(mu-tptz-H+)-}Ru(II)(acac)(NH=C(CH3)-OC2H5)]ClO4 ([7]ClO4), and [(acac)2Ru(III){(mu-tptz-Eta+)-}Ru(II)(acac)(NC4H4N)]ClO4 ([8]ClO(4))} complexes vary systematically depending on the electronic nature of the coordinated sixth ligands. However, potentials involving the Ru(III) center in the dinuclear complexes remain more or less invariant. The mixed-valent Ru(II)Ru(III) species ([5]ClO4-[8]ClO4) exhibits high comproportionation constant (Kc) values of 1.1 x 10(12)-2 x 10(9), with substantial contribution from the donor center asymmetry at the two metal sites. Complexes display Ru(II)- and Ru(III)-based metal-to-ligand and ligand-to-metal charge-transfer transitions, respectively, in the visible region and ligand-based transitions in the UV region. In spite of reasonably high K(c) values for [5]ClO4-[8]ClO4, the expected intervalence charge-transfer transitions did not resolve in the typical near-IR region up to 2000 nm. The paramagnetic Ru(II)Ru(III) species ([5]ClO4-[8]ClO4) displays rhombic electron paramagnetic resonance (EPR) spectra at 77 K (g approximately 2.15 and Deltag approximately 0.5), typical of a low-spin Ru(III) ion in a distorted octahedral environment. The one-electron-reduced tptz complexes [Ru(II)(tptz.-)(acac)(CEta3CN)] (1) and [(acac)2Ru(III){(mu-tptz-Eta+).2-}Ru(II)(acac)(CH3CN)] (5), however, show a free-radical-type EPR signal near g = 2.0 with partial metal contribution.     

Acenaphthylene-1,2-diamine radical cation. Molecular structure of the [(dpp-BIAN)H2]·+[X]− complex ((dpp-BIAN)H2 is N,N′-bis(2,6-diisopropylphenyl)-acenaphthylene-1,2-diamine; X = Cl or I)

Oxidation of N,N′-bis(2,6-diisopropylphenyl)acenaphthylene-1,2-diamine (dpp-BIAN)H₂ with silicon tetrachloride or mercury(II) chloride affords the [(dpp-BIAN)H₂]·⁺[Cl]⁻ compound. The corresponding iodine derivative, [(dpp-BIAN)H₂]·⁺[I]⁻, was prepared by hydrolysis of the reaction products of the magnesium complex (dpp-BIAN)Mg(THF)₃ with tetraiodosilane. X-ray diffraction study demonstrated that the [(dpp-BIAN)H₂]^·+ radical cation in these compounds chelates the corresponding halide anion. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 436–440, March, 2006.     

2,6-Bis(methylencyclopentadienyl)-pyridin-zirconocen- und -hafnocendichlorid; Bildung und Kristallstruktur von [C5H3N-2,6-(CH2?C5H4)2Zr(Cl)(OH2)]2[ZrCl6]

2,6-Bis(methylenecyclopentadienyl)-pyridine-zirconocene and -hafnocene Dichloride; Formation and Crystal Structure of [C₅H₃N-2,6-(CH₂? C₅H₄)₂Zr(Cl)(OH₂)[ZrCl₆]] Pyridine bridged metallocene dichlorides of type C₅H₃N-2,6-(CH₂? C₅H₄)₂MCl₂ (M = Zr ( 2 ), Hf ( 5 )) were synthesized. The presence of N → Zr interaction favours the formation of zirconocene cations. Traces of water cause the formation of the salt-like compound [C₅H₃N-2,6-(CH₂? C₅H₄)₂Zr(Cl)(OH₂)]₂[ZrCl₆] 4 from 2 . The new compounds were characterized by ¹H n.m.r., and mass spectroscopy. The X-ray crystal structure of 4 shows discrete cations and anions which are connected by H-bridges.     

Synthesis of 1-[(1,2-dithiol-3-ylidene)methyl]pyrrolo[1,2-a]pyrazines and 2-[(1,2-dithiol-3-ylidene)methyl]pyridines from 1,2-dithiole-3-thiones

Benzo- and pyridoannulated 1,2-dithiole-3-thiones react with compounds containing an activated methyl group such as 1-methyl-3,4-dihydropyrrolo[1,2-a]pyrazine and 2-methylpyridines to furnish substituted 1,2-dithiol-3-ylidenes.     

Protonation of magnesium and sodium complexes containing dianionic diimine ligands. Molecular structures of 1,2-bis{(2,6-diisopropylphenyl)imino}acenaphthene (dpp-BIAN), [(dph-BIAN)H<Subscript>2</Subscript>(Et<Subscript>2</Subscript>O)], and [(dpp-BIAN)HNa(Et<Subscript>2</Subscript>O)]

Hydrolysis of magnesium complexes containing the dianionic acenaphthenediimine ligands, (dpp-BIAN)Mg(thf)₃ (1), (dph-BIAN)Mg(thf)₃ (2), and (dtb-BIAN)Mg(thf)₂ (3) (dpp-BIAN is 1,2-bis{ (2,6-diisopropylphenyl)imino}acenaphthene; dph-BIAN is 1,2-bis{(2-diphenyl)imino}acenaphthene; dtb-BIAN is 1,2-bis{(2,5-di-tert-butylphenyl)imino}acenaphthene), affords the corresponding diamines (dpp-BIAN)H₂ (4), (dph-BIAN)H₂(Et₂O) (5), and (dtb-BIAN)H₂ (6). Compounds 4 and 5 were isolated in the crystalline state and characterized by UV-Vis, IR, and ¹H NMR spectroscopy. Partial hydrolysis of (dpp-BIAN)Na₂(Et₂O)₃ gave the crystalline (dpp-BIAN)HNa(Et₂O)₂ complex (7), which was also characterized by spectroscopic methods. The structures of compounds 5 and 7 and free diimine dpp-BIAN were established by X-ray diffraction analysis.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2634–2640, December, 2004.     

The Synthesis and Fungicidal Activities of 2,6-Bis[(3-aryl)-s-triazolo[3,4-b]-[1,3,4]thiadiazole-6-yl]pyridines

In search of better bioactive compounds, a series of novel 2,6-bis[(3-aryl)-s-triazolo[3,4-b]-[1,3,4]thiadiazole-6-yl]pyridines 2 were synthesized in high yields by the cyclization of 3-aryl-4-amino-5-mercapto-1, 2, 4-triazoles 1 with 2,6-pyridine dicarboxylic acid. 2 exhibited good fungicidal activities against Cerospora beticola sacc.     

Pt(0) and Pd(0) olefin complexes of the metalloid N-heterocyclic carbene analogues [E(I)(ddp)] (ddp=2-{(2,6-diisopropylphenyl)amino}-4-{(2,6-diisopropylphenyl)imino}-2-pentene; E=Al, Ga): ligand substitution, H--H and Si--H bond activation, and cluster formation

Various products of the reaction of [E(ddp)] (ddp=2-{(2,6-diisopropylphenyl)amino}-4-{(2,6-diisopropylphenyl)imino}-2-pentene; E=Al, Ga) with Pt(0) and Pd(0) olefin complexes are reported. Thus, the reaction of [Pt(cod)(2)] (cod=1,5-cyclooctadiene) with two equivalents of [Ga(ddp)] yields [Pt(1,3-cod){Ga(ddp)}(2)] (1), whereas treatment of [Pd(2)(dvds)(3)] (dvds=1,1,3,3-tetramethyl1,3-divinyldisiloxane) with [E(ddp)] leads to the monomeric compounds [(dvds)Pd{E(ddp)}] (E=Ga (2 a), Al (2 b)) by substitution of the bridging dvds ligand. Both 1 and 2 a readily react with strong pi-acceptor ligands such as CO or tBuNC to give the dimeric compounds [M{mu(2)-Ga(ddp)}(L)] (L=CO, tBuNC; M=Pt (3 a, 5 a), Pd (3 b, 5 b)), respectively. Based on (1)H NMR spectroscopic data, [Pt{Ga(ddp)}(2)(CO)] is likely to be an intermediate in the formation of 3 a. Furthermore, reactions of 1 with H(2) and HSiEt(3) yield the monomeric compounds [Pt{Ga(ddp)}(2)(H)(2)] (7) and [Pt{Ga(ddp)}(2)(H)(SiEt(3))] (8). Finally, the reaction of [Pt(cod)(2)] with one equivalent of [Ga(ddp)] in the presence of H(2) in hexane gives the new dimeric cluster [Pt{mu(2)-Ga(ddp)}(H)(2)](2) (9).     

Synthesis of [1,2-3H2]-polystyrene

The synthesis of [1,2-³H₂]-polystyrene consisted of a two step reaction. First catalytic tritium gas addition to phenylacetylene was used to prepare [1,2-³H₂]-styrene and then it was polymerized to [1,2-³H₂]-polystyrene in the present of an initiator.