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Publication Metadata only (Azido-kN)bis-(di-2-pyridylamine)-copper(II) hexa-fluoro-phosphate and (azido-kN)bis-(di-2-pyridylamine)-copper(II) chloride tetra-hydrate(2007-01-31) Sujittra Youngme; Jaturong Phatchimkun; Chaveng Pakawatchai; Samran Prabpai; Palangpon Kongsaeree; Khon Kaen University; Prince of Songkla University; Mahidol UniversityThe two new title complexes, [Cu(N3)(dpyam)2]PF6 (dpyam is di-2-pyridylamine, C10H11N3), (I), and [Cu(N3)(dpyam)2]Cl·4H2O, (II), respectively, have been characterized by single-crystal X-ray diffraction. Both complexes display a distorted square-pyramidal geometry. Each Cu atom is coordinated in the basal plane by three dpyam N atoms and one azide N atom in equatorial positions, and by another N atom from the dpyam group in the apical position. In complex (I), the one-dimensional supra-molecular architecture is assembled via hydrogen-bonding inter-actions between the amine N atom and terminal azide N atoms and the F atoms of the PF6 - anion. For complex (II), hydrogen-bonding inter-actions between the amine N atom, the Cl- anion and water O atoms result in a two-dimensional lattice. © 2007 International Union of Crystallography.Publication Metadata only Synthesis, spectroscopic characterization, X-ray crystal structure and magnetic properties of oxalato-bridged copper(II) dinuclear complexes with di-2-pyridylamine(2003-09-08) Sujittra Youngme; Gerard A. Van Albada; Narongsak Chaichit; Pimprapun Gunnasoot; Palangpon Kongsaeree; Ilpo Mutikainen; Olivier Roubeau; Jan Reedijk; Urho Turpeinen; Khon Kaen University; Thammasat University; Mahidol University; Gorlaeus Laboratories; Helsingin YliopistoThe syntheses and characterization of a series of dinuclear μ-oxalato copper(II) complexes of the general type [(NN)1or2Cu(C2O4)Cu(NN)1or2]2+, where NN=didentate dpyam (di-2-pyridylamine) ligand, are described. The crystal structures of three... and isostructural. The compound [Cu2(dpyam)2(C2O4)(NO3)2((CH3)2SO)2] (3) crystallizes in the centrosymmetric monoclinic space group P1 with all Cu-oxalate contacts in the equatorial plane. All three complexes contain six-coordinate copper centres bridged by planarPublication Metadata only Erratum: Synthesis, spectroscopic characterization, X-ray crystal structure and magnetic properties of oxalato-bridged copper(II) dinuclear complexes with di-2-pyridylamine (Inorganica Chimica Acta (2003) 353 (119-128) DOI: 10.1016/S0020-1693(03)00207-X)(2005-06-01) Sujittra Youngme; Gerard A. Van Albada; Narongsak Chaichit; Pimprapun Gunnasoot; Palangpon Kongsaeree; Ilpo Mutikainen; Olivier Roubeau; Jan Reedijk; Urho Turpeinen; Khon Kaen University; Thammasat University; Mahidol University; Gorlaeus Laboratories; Helsingin YliopistoPublication Metadata only Pyridine-triazole ligands for copper-catalyzed aerobic alcohol oxidation(2015-01-01) Pech Thongkam; Sudarat Jindabot; Samran Prabpai; Palangpon Kongsaeree; Taveechai Wititsuwannakul; Panida Surawatanawong; Preeyanuch Sangtrirutnugul; Mahidol University© The Royal Society of Chemistry 2015. A series of Cu(NN′)2(OTf)2 complexes containing pyridine-triazole ligands [OTf = OSO2CF3; NN′ = NN′Ph (1), NN′hex (2), NN′py (3)] with different substituents at the triazole N4 position or 2,2′-bipyridine (bpy; 4) have been synthesized. Crystal structures of 1 and 3 reveal a trans-isomer with strong preference for regular-type triazole coordination (for 3) whereas the Cu-bipyridine complex 4 is more stable in a cis-form. Cyclic voltammetry of 1-4 suggest that the electron-donating strength follows the trend: bpy > NN′py > NN′hex ∼ NN′Ph. The catalyst systems consisting of 5 mol% Cu(OTf)2/NN′/TEMPO (TEMPO = (2,2,6,6-tetramethylpiperidin-1-yl)oxy) in the presence of 2 × 2.0 cm2 Cu0 sheets as a reducing agent and 10 mol% N-methylimidazole (NMI) exhibit good activities for aerobic oxidation of benzyl alcohol to benzaldehyde. Catalytic studies have shown that the activities were higher with more electron-rich N-based ligands. Furthermore, oxidation of aliphatic alcohols such as 1-hexanol and 2-methyl-1-pentanol using the Cu catalyst system with the NN′py ligand at room temperature afforded the corresponding aldehydes in >99% and 46% yields, respectively after 24 h.Publication Metadata only Benzimidazole-triazole ligands with pendent triazole functionality: Unexpected formation and effects on copper-catalyzed aerobic alcohol oxidation(2016-01-01) Manisa Kongkaew; Kannika Sitthisuwannakul; Vasut Nakarajouyphon; Soraya Pornsuwan; Palangpon Kongsaeree; Preeyanuch Sangtrirutnugul; Mahidol University© 2016 The Royal Society of Chemistry. A series of benzimidazole-triazole ligands (NN′) having a pendent triazole arm with different triazole substituents including CH2Ph (3a), cyclo-C6H11(3b), and CH2SiMe3(3c) were obtained in moderate yields from Cu-catalyzed oxidative C-N cyclization of the respective amine-triazole compounds N,N′-bis((1-R-1,2,3-triazol-4-yl)methyl)benzene-1,2-diamine (2a-2c). Treatment of CuCl2with one equiv. of the benzimidazole-triazole ligands afforded the corresponding CuIIcomplexes with the empirical formula of Cu(NN′)Cl2(4a-4c). Crystal structures of 4b and 4c reveal mononuclear and dinuclear CuIIcomplexes, respectively. Despite the differences in triazole substituents and their solid state structures, ESR spectra indicate the same molecular structures in CH3CN solution whereas CV data suggest similar redox potentials for 4a-4c. Catalytic activities for aerobic oxidation of benzyl alcohol to benzaldehyde follow this trend: 4c > 4a > 4b. In addition, the catalytic system 4c/TEMPO/Cu0/NMI (TEMPO = 2,2,6,6-tetramethyl-1-piperidinyloxyl, NMI = N-methylimidazole) exhibited high activities for oxidation of activated alcohols (i.e., benzyl alcohol derivatives and allylic alcohol) in CH3CN at room temperature.Publication Metadata only Five-coordinate copper(II) complexes: Crystal structures, spectroscopic properties and new extended structural pathways of [Cu(chelate)2X]Y, where chelate = dpyam, phen and bipy; X = pseudohalide ligands(2008-05-15) Sujittra Youngme; Pongthipun Phuengphai; Chaveng Pakawatchai; Palangpon Kongsaeree; Narongsak Chaichit; Khon Kaen University; Rajabhat University; Prince of Songkla University; Mahidol University; Thammasat UniversityThe crystal structures of four distortion isomers of the [Cu(chelate)2 X]+cation, where chelate = 2,2-bipyridine (bipy), 1,10-phenanthroline (phen) and di-2-pyridylamine (dpyam), X = a pseudohalide ligand (NCO, NCS, N3 and C2N3), have been compared by scatterplot analysis with 25 [Cu(chelate)2 X]Y complexes of known crystal structure. The four new complexes [Cu(phen)2NCO]Br (1), [Cu(phen)2N3]BPh4·H2O (2), [Cu(dpyam)2(N3)]NO3·H2O (3) and [Cu(dpyam)2(N3)]ClO4 (4) involve a near regular square-based pyramidal stereochemistry (RSBP). The structures of complexes (1) and (2) are of the rare cases found for the phen analogue. Scatterplots of the 29 cation distortion isomers of the [Cu(chelate)2 X]Y series of complexes suggest that most of the 29 complexes lie on a common structural pathway, involving a mixture of the symmetric, C 2, and the asymmetric, non-C 2, in-plane modes of vibration of the CuN4N′ chromophore. Some datapoints are found to lie on extended routes The resulting structural pathways are consistent with the direct observation of the effect of the modes of vibration on the stereochemistries of the complexes. A comparison of the trends in the 29 datasets suggests a size effect of the phen, bipy and dpyam ligands. © 2008 International Union of Crystallography.Publication Metadata only Bis[2,6-bis(2-methoxyphenyl)pyridinium] di-μ-bromido-bis- [dibromidocuprate(II)](2011-03-01) Preeyanuch Sangtrirutnugul; Setsiri Haesuwannakij; Thanasat Sooksimuang; Samran Prabpai; Palangpon Kongsaeree; Mahidol University; Thailand National Metal and Materials Technology CenterThe title salt, (C 19 H 18 NO 2 ) 2 [Cu 2 Br 6 ], was obtained from an attempt to synthesize the copper(II) complex of 2,6-bis(2-methoxyphenyl)pyridine (L) from a reaction between CuBr 2 and one equivalent of L in CH 2 Cl 2 at room temperature... result of intra-molecular N - H⋯O hydrogen bonds. The centrosymmetric hexabromidodicuprate dianion possesses a distorted tetrahedral geometry at the copper ion. The Cu - Br bond lengths are 2.3385 (7) and 2.3304 (7) Å for the terminal bromides, whereasPublication Metadata only A rhodamine–bistriazole based fluorescent and colorimetric sensor containing a phenyl linker for Fe(III) detection(2020-01-01) Kanokorn Wechakorn; Sinchai Chomngam; Utt Eiamprasert; Palangpon Kongsaeree; Rajamangala University of Technology Thanyaburi (RMUTT); Mahidol University© 2020, Institute of Chemistry, Slovak Academy of Sciences. A rhodamine-based fluorescent sensor bearing 1,2-phenylenediamine linked to a bistriazole moiety was designed and synthesized through the copper(I)-catalyzed click chemistryPublication Metadata only Synthesis, structure, spectroscopy, and magnetism of two new dinuclear carbonato-bridged Cu(II) complexes(2001-11-12) Sujittra Youngme; Narongsak Chaichit; Palangpon Kongsaeree; Gerard A. Van Albada; Jan Reedijk; Khon Kaen University; Thammasat University; Mahidol University; Gorlaeus Laboratoriespyramidal geometry for each Cu(II) environment. Complex 2 involves the di-μ-CO32-bridge with a novel tridentate μ-η1-η2-CO32-coordination mode. The geometry around each copper atom is distorted square-based pyramidal. Susceptibility measurements for both