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Öğe Synthesis of a water-soluble carbene complex and its use as catalyst for the synthesis of 2,3-dimethylfuran(Elsevier Science Sa, 2001) Özdemir, I; Yigit, B; Cetinkaya, B; Ülkü, D; Tahir, MN; Arici, C1,1,3,3'-Tetrakis(p-dimethylaminobenzyl)-2,2'-biimidazolidinylidene, L-2(R) (R = CH2C6H4NMe2-p) which contains four peripheral NMe2 substituents, was obtained from 4-dimethylaminobenzaldehyde by a three-step reaction sequence, and was used for the preparation of imidazolidin-2-ylidene Ru(II) and Rh(I) complexes 1 and 2. Etherial HCl readily protonates the NMe2 functionality on the carbene ligand of 1 to give the corresponding salt, 1'; whereas the reaction of 2 with HCl gave a hygroscopic and ill-defined rhodium species. In aqueous solution the salt 1' is an efficient and active catalyst for intramolecular cyclisation of (Z)-3-methylpent-2-en-4-yn-1-ol into 2,3-dimethylfuran. The catalyst 1' could be recovered by simple phase separation and the catalytic reaction was maintained for five different runs. All of the new compounds were characterised by elemental analyses, IR and NMR spectroscopy and the molecular structure of I was determined by X-ray crystallography. (C) 2001 Elsevier Science B.V. All rights reserved.Öğe Synthesis, structure and spectroscopic characterization of 1,2-bis-(2,4,6-trimethylbenzylideneamino) ethanedichloropalladium(II)(Taylor & Francis Ltd, 2006) Arici, C; Ülkü, D; Özdemir, I; Demir, S; Çetinkaya, BThe structure of 1,2-bis(2,4,6-trimethylbenzylideneamino)ethanedichloropalladium(II) was determined by X-ray diffraction methods. The structure derived from NMR and IR spectra and elemental analysis is consistent with it. The complex is orthorhombic, space group Pcab, with a = 14.8662(12), b = 15.0861(13), c = 20.6255(14) angstrom, V = 4625.7(6) angstrom(3) and Z = 8. In the lattice, there exists a weak C-H center dot center dot center dot Cl hydrogen bond.