N. M. Khvoinova

New high-spin iron complexes based on bis(imino)acenaphthenes (BIAN): synthesis, structure, and magnetic properties

The reactions of iron diiodide with one and two equivalents of the monopotassium salt of 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene (dpp-BIAN) in diethyl ether gave the complexes [(dpp-BIAN)FeI]2 (1) and (dpp-BIAN)2Fe (2), respectively. The bis-ligand complex (tms-BIAN)2Fe (3) was synthesized by the exchange reaction of the monosodium salt of 1,2-bis(trimethylsilylimino)acenaphthene (tms-BIAN) with iron diiodide. The reaction of FeI2 with tms-BIAN affords the chelate complex (tms-BIAN)FeI2 (4), whereas the reaction of FeBr2·2H2O with tms-BIAN is accompanied by elimination of trimethylsilyl groups to form the tris-ligand acenaphthene-1,2-diimine complex [(H2BIAN)3Fe][FeBr3·THF]2 (5) containing two types of iron ions. Compounds 1–5 were characterized by IR spectroscopy and elemental analysis. The molecular structures of 1–5 were determined by single-crystal X-ray diffraction. For high-spin complexes 1–3, the temperature-dependent magnetic susceptibilities were measured in the range of 4–300 K.

Hydroamination of alkynes with aromatic amines catalyzed by digallane (dpp-bian)Ga—Ga(dpp-bian)

Digallane (dpp-bian)Ga—Ga(dpp-bian) (1) (dpp-bian is the 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene) catalyzes the addition of 4-chloroaniline to some terminal alkynes RC≡CH (R = Bun, Ph, 4-MeC6H4). The reaction orders in each of the substrates were found for the reaction of phenylacetylene with 4-chloroaniline catalyzed by compound 1. The reaction of compound 1 with phenylacetylene in a molar ratio of 1: 10 led to 1-[N-(2,6-diisopropylphenyl)imino]-2-(1-phenylethylidene)acenaphthene (5) and the compound [C12H6(NC6H3Pr2i)(PhC=CH2)(PhC=CH)]Ga(C≡CPh)2 (6). The reaction of digallane 1 with phenylacetylene and aniline in a stoichiometric ratio of 1: 2: 2 gave bis-anilide (dpp-bian)-Ga[N(H)Ph]2 (7) in 40% yield. The compound (PhC≡C)3Ga·THF (9) was obtained by the reaction of three equivalents of sodium phenylacetylide (prepared in situ from phenylacetylene and sodium) with one equivalent of GaCl3 in tetrahydrofuran. Compounds 5—7 and 9 were characterized by IR spectroscopy, 1H NMR spectroscopy was used to characterize products 5, 6, and 9, whereas EPR spectroscopy was used for amide 7. The structures of compounds 5—7 and 9 were determined by single crystal X-ray diffraction analysis.

Syntheses and structures of magnesium, calcium, europium, gallium, and zinc complexes with bis(imino)acenaphthene ligands*

The reduction of 1,2-bis(trimethylsilylimino)acenaphthene and 1,2-bis{[3,5-bis(trifluoromethylphenyl)]imino}acenaphthene with metals gave magnesium, calcium, europium, zinc, and gallium complexes containing radical-anion and dianionic ligands of the 1,2-diiminoacenaphthene type. Their structures were studied by 1H NMR, ESR, and/or single-crystal X-ray analysis. Some chemical transformations of the complexes were carried out.

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.