Synthesis, structures, electrochemical and quantum chemical investigations of Ni(ii) and Cu(ii) complexes with a tetradentate Schiff base derived from 1-(2-thienyl)-1,3-butanedione

Abstract

Electrochemical oxidation of four-coordinate square planar Schiff-base Ni(ii) and Cu(ii) complexes leads to the formation of oligomers at the electrode.

Synthesis of β‐Ketoiminato Copper(II) Complexes and Their Use in Copper Deposition

“…The C=O and C=N vibrations for 6 and 8 are found at 1587 and 1503 cm –1 ( 6 ) as well as 1541 and 1514 cm –1 ( 8 ). Upon coordination of 3 / 4 or 7 to Cu II these bands are shifted to lower wavenumbers confirming the formation of complexes 6 and 8 , , , and hence IR spectroscopy can be used to monitor the progress of the respective reaction. In addition, the coordination of 3 / 4 to Cu II to give 6 is accompanied by the disappearance of the ν(N–H) band at 3200 cm –1 , …”

“…Hydrogen bond formation in complex 8 was confirmed by the appearance of weak and broad ν(N-H) absorptions at around 3200 cm -1 in the IR spectra (see Experimental Section), evidencing that not both β-ketoiminato units of L in 8 are complexed to Cu 2+ , which is in accordance with the solidstate structure (vide infra). From IR spectroscopy it also can be concluded that the enamine tautomer is favored over the imine form in the non-coordinated side of L in 8, [58][59][60][61][62][63] due to weak bands at 3461 cm -1 (8). [58][59][60][61][62][63] Further strong absorptions for 3/4 are found at 1599 and 1565 cm -1 , which can be assigned to the respective C=O and C=C stretching vibrations ARTICLE (see Experimental Section).…”

“…From IR spectroscopy it also can be concluded that the enamine tautomer is favored over the imine form in the non-coordinated side of L in 8, [58][59][60][61][62][63] due to weak bands at 3461 cm -1 (8). [58][59][60][61][62][63] Further strong absorptions for 3/4 are found at 1599 and 1565 cm -1 , which can be assigned to the respective C=O and C=C stretching vibrations ARTICLE (see Experimental Section). The C=O and C=N vibrations for 6 and 8 are found at 1587 and 1503 cm -1 (6) as well as 1541 and 1514 cm -1 (8).…”

“…The observed bond lengths within the square-planar coordination sphere between Cu-N and Cu-O of approximately 1.9 Å are in good agreement with other Cu II complexes ( Table 2). [58,59,64,66,68] The six-membered metallacycle CuC 3 NO is significantly bent (rms values of up to 0.0585) and shows plane intersections of 6.4 (14) and 9.3(14)°.…”

Bis‐β‐(diketonates) Zn(II) complexes substituted with thiophene: Electropolymerization, homogeneous and heterogeneous catalysis for ring opening polymerization of lactide

“…1‐(thiophen‐2‐yl)butane‐1,3‐dione and 1‐(thiophen‐2‐yl)‐3‐(thiophen‐3‐yl)propane‐1,3‐dione was synthesized by a reported procedure . The synthesis reactions were performed under dry dinitrogen atmosphere using standard Schlenk technique.…”