The Cu(I), Ag(I), and Au(I) chemistry of a tetradentate ligand (phenylene-1,4-diaminotetra(phosphonite), p-C(6)H(4)[N{P(OC(6)H(4)OMe-o)(2)}(2)](2) (P(2)NPhiNP(2)) (1)) is described. The flexional conformations in 1 leads to interesting structural variations in transition-metal complexes. The reaction of 1 with 4 equiv of CuX (where X = Br and I) produce the tetranuclear complexes, [{Cu(2)(mu-X)(2)(NCCH(3))(2)}(2)(mu-P(2)NPhiNP(2))] (where X = Br (2) or X = I (3)) in quantitative yield. Treatment of 3 with an excess of pyridine, 2-(piperazin-1-yl)pyrimidine, and pyrazole yielded the tetra-substituted derivatives, [{Cu(2)(mu-I)(2)(L)(2)}(2)(mu-P(2)NPhiNP(2))] (where L = pyridine (4), 2-(piperazin-1-yl)pyrimidine (5), or pyrazole (6)). Similar reactions of 3 with 1,10-phenanthroline (phen) and 2,2'-bipyridine in a 1:2 molar ratio afford the disubstituted derivatives, [(Cu(2)(mu-I))(2)I(2)(phen)(2)(mu-P(2)NPhiNP(2))] (7) and [(Cu(2)(mu-I))(2)I(2)(bipy)(2)(mu-P(2)NPhiNP(2))] (8). The o-methoxyphenoxy substituents on phosphorus in complexes 5 and 7 adopt approximately parallel planar conformations and contain lattice solvents. The reaction of 3 with 1,4-diazabicyclo[2.2.2]octane (DABCO) in a 1:2 molar ratio in a dichloromethane-acetonitrile mixture leads to the formation of an ionic complex [N(CH(2)CH(2))(3)N(+)CH(2)Cl](2)[(Cu(2)(Cl)(I)(2))(2)(NCCH(3))(2)(mu-P(2)NPhiNP(2))](2-) (9), as a result of the chloromethylation of DABCO. Treatment of 1 with 4 equiv of AgClO(4) produces [{Ag(2)(mu-ClO(4))(2))(2)(C(4)H(8)O)(2)}(2)(mu-P(2)NPhiNP(2))] (10). Displacement of perchlorate ions in 10 by PhN{P(OC(6)H(4)OMe-o)(2)}(2) (PNP) or 2,2'-bipyridine yielded [(mu-PNP)(2)Ag(2)(mu-P(2)NPhiNP(2))Ag(2)(mu-PNP)(2)](ClO(4))(4) (11) and [{Ag(2)(bipy)(2)}(2)(mu-P(2)NPhiNP(2))](ClO(4))(4) (12), respectively. The similar reaction of 1 with 2 equiv of AgOTf, in the presence of 4,4'-bipyridine, gave a three-dimensional Ag(I) coordination polymer, [{Ag(2)(C(10)H(8)N(2))(2)(CH(3)CN)(2)}(2)(P(2)NPhiNP(2))](n)(OTf)(4n) (13). The reactions of 1 with [AuCl(SMe(2))], in appropriate ratios, afford the tetranuclear and dinuclear complexes, [(Au(2)Cl(2))(2)(mu-P(2)NPhiNP(2))] (14) and [(AuCl)(2)(P(2)NPhiNP(2))] (15). Complex 14 undergoes moisture-assisted P-N bond cleavage in the presence of PhN{P(OC(6)H(4)OMe-o)(2)}(2) to give [p-NH(2)C(6)H(4)N{P(OC(6)H(4)OMe-o)(2)}(2)Au(2)Cl(2)] (17) and [PhN{P(OC(6)H(4)OMe-o)(2)}(2)Au(2)Cl(2)]. The structures of the complexes 5, 7-10, 12-15, and 17 are confirmed by single-crystal X-ray diffraction studies.
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http://dx.doi.org/10.1021/ic900085e | DOI Listing |
Bioelectrochemistry
December 2024
Department of Engineering, University of Messina, I-98166 Messina, Italy. Electronic address:
In this investigation, a novel tetradentate Schiff base ligand, (ligand L) was synthesized using a simple chemical route assisted by triethylenetetramine with 4-dimethylaminocinnamaldehyde in ethanol. The chemical structure of the as-synthesized ligand was characterized using nuclear magnetic resonance (NMR) and UV-visible spectroscopy. This ligand was then employed to modify the working electrode of screen-printed carbon electrode (SPCE) for developing a modified L/SPCE sensor finalized to detection of lead ions (Pb).
View Article and Find Full Text PDFACS Nano
December 2024
Department of Chemistry, Korea University, Seoul 02841, Republic of Korea.
Research on perovskite light-emitting diodes (PeLEDs) has primarily focused on modulating crystal growth to achieve smaller grain sizes and defect passivation using organic additives. However, challenges remain in controlling the intermolecular interactions between these organic additives and perovskite precursor ions for precise modulation of crystal growth. In this study, we synthesize two triphenylphosphine oxide (TPPO)-based multidentate additives: bidentate hexane-1,6-diyl-bis(oxy-4-triphenylphosphine oxide) (2-TPPO) and tetradentate pentaerythrityl-tetrakis(oxy-4-triphenylphosphine oxide) (4-TPPO).
View Article and Find Full Text PDFACS Omega
December 2024
Department of Chemistry, Panskura Banamali College, Panskura RS, West Bengal 721152, India.
In this study, a tetradentate Schiff-base ligand (HL), synthesized by the condensation of ethylenediamine with 2-hydroxy-3-methoxy-5-methylbenzaldehyde, was reacted with either manganese salts or manganese salts in the presence of various pseudohalides in methanol. This reaction resulted in the formation of five mononuclear Mn complexes: [Mn(L)(HO)](NO)·1/2HO·1/2CHOH (), [Mn(L)(HO)](ClO)·HO (), [Mn(L)(N)(HO)]·1/3HO (), [Mn(L)(NCS)(HO)] (), and [Mn(L)(HO)](dca) () (where dca is dicyanamide ion). X-ray crystallography revealed that the Mn centers adopt a hexa-coordinate pseudo-octahedral geometry, where the equatorial plane is constructed with phenoxo oxygen and imine nitrogen atoms from the Schiff base ligand, while the axial positions are occupied by water molecules or a combination of water and pseudohalides.
View Article and Find Full Text PDFJ Inorg Biochem
December 2024
Department of Molecular and Analytical Chemistry, Interdisciplinary Excellence Centre, University of Szeged, Dóm tér 7-8, H-6720 Szeged, Hungary. Electronic address:
Schiff bases derived from aminoguanidine are extensively investigated for their structural versatility. The tridentate 2-formylpyridine guanylhydrazones act as analogues of 2-formyl or 2-acetylpyridine thiosemicarbazones, where the thioamide unit is replaced by the guanidyl group. Six derivatives of 2-formylpyridine guanylhydrazone were synthesized and their proton dissociation and complex formation processes with Cu(II), Fe(II) and Fe(III) ions were studied using pH-potentiometry, UV-visible, NMR and electron paramagnetic resonance spectroscopic methods.
View Article and Find Full Text PDFJ Colloid Interface Sci
December 2024
Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China.
Electron effect regulation is a crucial factor influencing the activity and selectivity of Cu-based coordination compound catalysts in the electrochemical carbon dioxide reduction reaction (CORR). Despite significant progress, the structure-activity relationship and the underlying regulatory mechanisms warrant further in-depth investigation. In this study, three types of Cu-[ONNO] tetradentate coordination molecular catalysts with varying electron densities, namely Cu-NO, methoxy-modified Cu-NO (Cu-EDG-NO), and nitro-modified Cu-NO (Cu-EWG-NO), were prepared using a substituent regulation strategy.
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