Investigation of a mercury(II) carbene complex: bis(1,3-dimethylimidazol-2-ylidene) mercury chloride

The reaction of 1,3-dimethylimidazolium chloride with Hg(O₂CCH₃)₂ afforded a bis(carbene)mercury(II) complex (2), which is characterized by multinuclear NMR spectroscopy (¹H, ¹³C, ¹⁵N, and ¹⁹⁹Hg) and by single-crystal X-ray analysis. As a consequence of chloride-ion interaction with the mercury center, the C₂-Hg-C₂ angle in 2 is reduced to 161.4 (3)° compared to its near-linear value in complex 4 that contains perchlorate counterions. The C₂ resonance in the mercury complex 2 moves upfield by 36.96 ppm relative to the parent carbene (2), with a large ¹J_HgC = 2741.18 Hz. © 1996 John Wiley & Sons, Inc.     

STRUCTURE OF 3-(IMIDAZOLIDIN-2-YLIDENE)-4,5-DIMETHYL-4,5-DIHYDRO-2(3H)-FURANONE, C_9H_(14)O_2N_2

<正> Mr=182.25, Orthorhombic, Pna21, a=10.698(4), b=9.779(4), c=8.872(5)A, Z=4, V=928.1(7)A3, Dx=1.3 Mgm-3, λ(MoKα)=0 . 71069A, μ(MoKα) = 1.0cm-1, F(000)=392, room temperature, R=0.034 for 637 reflections. The lactone ring and imidazolidine ring are twisted mutually by 12.3°. The two methyl groups are in cis positions relative to the lactone ring. There exist intramolecular and intermolecular hydrogen bonds in the structure.     

Synthesis of (2-Amino-4,5-dimethylcyclohexyl)phosphonic Acid

Russian Journal of General Chemistry -     

A new class of organosuperbases, N-alkyl- and N-aryl-1,3-dialkyl-4,5-dimethylimidazol-2-ylidene amines: synthesis, structure, pK(BH+) measurements, and properties

A series of stable organosuperbases, N-alkyl- and N-aryl-1,3-dialkyl-4,5-dimethylimidazol-2-ylidene amines, were efficiently synthesized from N,N'-dialkylthioureas and 3-hydroxy-2-butanone and their basicities were measured in acetonitrile. The derivatives with tert-alkyl groups on the imino nitrogen were found to be more basic than the tBuP(1) (pyrr) phosphazene base in acetonitrile. The origin of the high basicity of these compounds is discussed. In acetonitrile and in the gas phase, the basicity of the alkylimino derivatives depends on the size of the substituent at the imino group, which influences the degree of aromatization of the imidazole ring, as measured by (13)C?NMR chemical shifts or by the calculated ΔNICS(1) aromaticity parameters, as well as on solvation effects. If a wider range of imino-substituents, including electron-acceptor substituents, is treated in the analysis then the influence of aromatization is less predominant and the gas-phase basicity becomes more dependent on the field-inductive effect, polarizability, and resonance effects of the substituent.     

Synthesis and Properties of Copper(II) Tetra(2-alkyl-4,5-benzimidazolo)- and Tetra(2,2'-Dimethyl-4,5-benzodiazepino)porphyrazines

4,5-Diaminophthalonitrile was reacted with carboxylic acids and acetylacetone to synthesize 2-alkyl-5,6-dicyanobenzimidazoles and 2,2'-dimethyl-5,6-dicyanobenzodiazepine, respectively. The products were converted into copper(II) porphyrazines. An effect of the heterocyclic residue on the physicochemical and spectral properties of the porphyrazines was revealed.     

Luminescent zinc(II) and cadmium(II) complexes based on 2-(4,5-dimethyl-1H-imidazol-2-yl)pyridine and 2-(1-hydroxy-4,5-dimethyl-1H-imidazol-2-yl)pyridine

Complexes ZnL¹Cl₂, CdL¹Cl₂, ZnL ₂ ¹ Cl₂ ^·1.5H₂O, CdL ₂ ¹ Cl₂ ^·2H₂O, CdL ₂ ¹ Cl₂ ^·MeOH·H₂O [L¹ = 2-(4,5-dimethyl-1H-imidazol-2-yl)pyridine] and inner-complex compounds ZnL ₂ ² ·2H₂O, CdL ₂ ² [HL² = 2-(1-hydroxy-4,5-dimethyl-1H-imidazol-2-yl)pyridine] were synthesized. The complexes exhibit bright photoluminescence in the blue region of the spectrum, with the intensity exceeding this characteristic of the compounds L¹ and HL². Compound L¹ in aqueous solution is a potential chemosensor for the determination of zinc and cadmium.