Influence of the counterion on the geometry of Cu(I) and Cu(II) complexes with 1,10-phenanthroline

• Published in: Inorganica Chimica Acta 2018-01, Vol.470, p.342-351
• Main Authors: Crispini, Alessandra, Cretu, Carmen, Aparaschivei, Diana, Andelescu, Adelina A., Sasca, Viorel, Badea, Valentin, Aiello, Iolinda, Szerb, Elisabeta I., Costisor, Otilia
• Format: Article
• Language: English
• Subjects: 1,10-Phenanthroline; Absorption spectroscopy; Atomic absorption analysis; Atomic beam spectroscopy; Atomic structure; Copper(I) and Cu(II) complexes; Counterion influence; Crystal structure; Diffraction; Molecular chains; Molecular structure; NMR; Nuclear magnetic resonance; Single crystals; Stereochemistry; Thermogravimetric analysis; X-ray crystallography; X-ray diffraction
• ISSN: 0020-1693; 1873-3255
• DOI: 10.1016/j.ica.2017.05.064

Guiding the molecular stereochemistry with counterions. [Display omitted] •Synthesis of Cu(I)/Cu(II) unsubstituted phen-based complexes.•Influence of the counterion on the molecular geometry and stereochemistry.•Structural distortion of Cu(I)/Cu(II) ionic complexes by means of counterions.•Coordination stereochemistry of Cu(I)/Cu(II)) ionic complexes driven by counterions. The influence of the counterions on the geometry of Cu(I) and Cu(II) unsubstituted phen-based (phen=1,10-phenanthroline) complexes was investigated. The synthetic strategy used afforded the synthesis of both the tetracoordinated Cu(I) and pentacoordinated Cu(II) species with general formula [(phen)2Cu]+Y− (Y−=ClO4−, I−, SCN− and BF4−) and [(phen)2CuX]+Y− (X=Cl−, I−, NCS−, and Y−=ClO4−, I−, SCN− and BF4−), respectively. The firstly isolated Cu(I) complexes were characterized by IR, 1H NMR and UV-Vis spectroscopies, their proposed structures being confirmed by elemental analysis, atomic absorption spectroscopy (AAS) and thermogravimetric analysis (TGA). The molecular structure of Cu(II) complexes was determined by single crystal X-ray diffraction analysis. While for Cu(I) complexes, the coordinating nature of the counterions seems to have a strong influence (observed in the solid state and concentrated solution) on the flattening distortion (D2d→D2) of the geometry about the Cu(I) ion, in the Cu(II) derivatives, the size, shape, number and type of intermolecular interactions established by the counterions, drive not only the overall cations supramolecular organization, but also the molecular stereochemistry around the Cu(II) ion.