Thermodynamics of lanthanide(III) complexation with ethylenediamine in dimethyl sulfoxide

Cobalt(II) Complexes with Nitrogen Donors and Their Dioxygen Affinity in Dimethyl Sulfoxide

“…If the change occurred, in fact, abnormally less unfavourable entropy and less favourable enthalpy values would be expected. [30] A comparison between the stability constant associated with the first complexation step for the Co II Ϫen and Ϫn-but systems (Table 1) shows that it is much higher for the former ligand, indicating that the en ligand behaves as bidentate; the very exothermic value of the ∆H°β 1 and the unfavourable entropy terms are in line with this hypothesis, which is further confirmed by FT-IR spectra run on solutions containing Co II Ϫen in a molar ratio 1:0.5 where no bands typical of free ϪNH 2 groups [36,37] were detected.…”

Solvothermal Synthesis, Crystal Structures, and Properties of New Selenidoantimonates [Ln(en)4(SbSe4)] (Ln = La, Nd) and [Sm(en)4]SbSe4·0.5en: The First Example of an SbSe43– Anion Acting as a Ligand to a Lanthanide Complex

“…In 1 and 2 ,[Ln(en) 4 ] 3+ (Ln = La, Nd) cations combine with SbSe 4 3– through an Ln–Se bond, while [Sm(en) 4 ] 3+ does not bond with SbSe 4 3– in 3 . Although the lanthanide(III) ions do not exhibit restricted stereochemistry in coordination complexes and are characterized by variable coordination numbers and geometries in the solid state,36 it is commonly observed that the lighter lanthanide ions prefer coordination numbers of nine and heavier ones prefer coordination numbers of eight in solution 37. Because en is a bidentate ligand, the [La(en) 4 ] 3+ and [Nd(en) 4 ] 3+ ions are bonded to the monodentate ligand SbSe 4 3– to maintain the coordination number of nine for La 3+ and Nd 3+ , and [La(en) 4 (SbSe 4 )] and [Nd(en) 4 (SbSe 4 )] are formed.…”

Synthesis, solvatochromism and crystal structure of trans -[Cu(Et 2 NCH 2 CH 2 NH 2 ) 2 .H 2 O](NO 3 ) 2 complex: Experimental with DFT combination

“…The geometry of five-coordinate complexes ranges between square pyramidal (SP) and trigonal bipyramidal (TBP). Very few copper(II) complexes with regular TBP geometry are known, with the exception of some complexes containing tripodal ligands [24].…”