Author: Larisa Oresmaa

0000000000515225

AUTHOR

Larisa Oresmaa

Triazenides as Suitable Ligands in the Synthesis of Palladium Compounds in Three Different Oxidation States: I, II, and III

New orthometalated dinuclear triazenide palladium(II) compounds of the general formula Pd2[(C6H4)PPh2]2[R–N–N–N–R]2 (R = C6H5, 3a; o-BrC6H4, o-3b; o-MeOC6H4, o-3c; o-MeC6H4, o-3d ; p-BrC6H4, p-3b; p-MeOC6H4, p-3c; p-MeC6H4, p-3d) have been synthesized and structurally characterized. The characteristics of these compounds were compared with the isoelectronic formamidinate derivatives. These triazenide compounds have been suitable starting products in the synthesis of new not so common dinuclear palladium(I) compounds and new unusual palladium(III) ones. In the presence of an excess of the triazenide ligand, compounds o-3b and o-3c underwent a reduction process giving dinuclear palladium(I) c…

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The geometry of the silver 1,1′-dibenzyl-2,2′-biimidazole complexes

Abstract The argentophilic interactions and interactions of weakly coordinated nitrate and water with silver metal were studied by investigating the reaction of 1,1′-dibenzyl-2,2′-biimidazole (Bn2bim) with silver nitrate. Three new silver complexes [Ag4(Bn2bim)4(NO3)2]·4(CH3CH2OH)·2(NO3)·0.5(H2O) (1), [Ag4(Bn2bim)4(H2O)4]·4(NO3) (2) and [Ag4(Bn2bim)4(NO3)4]·6(CH2Cl2)·2(H2O) (3) were synthesized and characterized. Complexes 1-3 have rare tetranuclear twisted closed cyclic structure with four bridging biimidazoles and variable nitrate/water ratio. The interactions between the nitrate ligand and Ag as well as water ligands and Ag are considered to be weak due to the ease of exchanging them. Th…

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Electro- and Photo-driven Reduction of CO 2 by a trans -(Cl)-[Os(diimine)(CO) 2 Cl 2 ] Precursor Catalyst: Influence of the Diimine Substituent and Activation Mode on CO/HCOO − Selectivity

A series of [OsII(NN)(CO)2Cl2] complexes where NN is a 2,2′-bipyridine ligand substituted in the 4,4′ positions by H (C1), CH3 (C2), C(CH3)3 (C3), or C(O)OCH(CH3)2 (C4) has been studied as catalysts for the reduction of CO2. Electrocatalysis shows that the selectivity of the reaction can be switched toward the production of CO or HCOO− with an electron-donating (C2, C3) or -withdrawing (C4) substituent, respectively. The electrocatalytic process is a result of the formation of an Os0-bonded polymer, which was characterized by electrochemistry, UV/Visible and EPR spectroscopies. Photolysis of the complexes under CO2 in DMF+TEOA produces CO as a major product with a remarkably stable turnover…

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Metallophilic interactions in stacked dinuclear rhodium 2,2'-biimidazole carbonyl complexes

Non-covalent metallophilic interactions were studied by investigating the stacking of two neutral rhodium complexes [Rh2I(R2bim)Cl2(CO)4] (R = Et, ethyl or Pr, propyl) in the solid state. Both dinuclear complexes formed infinite arrays of square planar d8 rhodium centres with intramolecular Rh⋯Rh distances of 3.1781(5) A (R = Et) and 3.1469(3) A (R = Pr) and the intermolecular Rh⋯Rh distances of 3.4345(6) A (R = Et) and 3.4403(3) A (R = Pr) between the adjacent molecules. The crystalline solids were stable and did not contain any solvent of crystallization. The effect of the metallophilic interactions on the absorption properties were studied using TD-DFT methods. The computational results …

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Neutral one-dimensional metal chains consisting of alternating anionic and cationic rhodium complexes.

The metallophilic interactions were investigated within chains of oppositely charged rhodium carbonyl complexes. The cationic [Rh(CO)(2)(L)](+) (L = 2,2'-bipyridine and 1,10-phenanthroline) and anionic [RhCl(2)(CO)(2)](-) units were self-assembled into one dimensional rhodium chains supported by electrostatic interactions. The array of Rh centers in {[Rh(CO)(2)(2,2'-bpy)][RhCl(2)(CO)(2)]}(n) was found to be nearly linear with a Rh···Rh···Rh angle of 170.927(11)° and Rh···Rh distances of 3.3174(5) Å and 3.4116(5) Å. The crystal structure of {[Rh(CO)(2)(1,10-phen)][RhCl(2)(CO)(2)]} consisted of two sets of crystallographically independent chains with slightly different Rh···Rh···Rh angles (17…

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