Structures of Bis(5,5-diphenylhydantoinato)copper(II) Complexes with Primary Amines Involving Square Pyramidal CuN4O Chromophores

Abstract

Copper(II) complexes [CuL2(i-PrNH2)2·H2O] (1a), [CuL2(i-PrNH2)2] (1b), [CuL2(EtNH2)2·H2O] (2a), [CuL2(EtNH2)2]·CHCl3 (2b), [CuL2(EtNH2)2·H2O]·2CHCl3 (2c), and [CuL2(EtNH2)2·MeOH] (2d) (L = 5,5-diphenylhydantoinate) have been prepared. The crystal structures of 1a, 2c, and 2d were determined by X-ray analysis. Each CuN4O chromophore is a five-coordinated square-based pyramidal geometry. The axial Cu–O distances are Cu(1)–O(1)(water) = 2.362(10) Å, Cu(1)–O(1)(water) = 2.436(9) Å and Cu(1)–O(1)(MeOH) = 2.33(1) Å, for complexes 1a, 2c, and 2d, respectively. Intramolecular hydrogen bonds are formed between the carbonyl oxygens and amino hydrogens (C=O···H–N) as well as the axial ligand (C=O···H–O). The latter hydrogen bonds stabilize the axial ligand for coordination. Moreover, double intermolecular hydrogen bonds link the 5,5-diphenylhydantoinate ligands (C=O···H–N) belonging to be adjacent complex molecules in all three complexes. The electronic spectra of the complexes in the solid state and in chloroform solutions were determined at room temperature, and a considerable change in ligand field bands was observed. The five-coordinated complexes in the chloroform solutions release their axial water ligand and the CuN4O chromophore converts into a distorted tetrahedral CuN4 chromophore.

Bis(2,4-dioxo-5,5-diphenylimidazolidinido-κN3)bis(propane-1,3-diamine-κ2N,N′)cobalt(II)

“…Xilan Hu, Qing Jiang, Daqi Wang and Haifeng Liu S1. Comment 5,5-Diphenylimidazoline-2,4-dione (phenytoin) is a widely used drug in the treatment of epilepsy and an excellent ligand for transition metal complexes (Milne et al, 1999;Akitsu et al, 1997;Akitsu & Einaga, 2005). As a continuation of our research devoted to the design and synthesis of complexes with 5,5-diphenylhydantoinate (Hu et al, 2006(Hu et al, , 2007(Hu et al, , 2009, we report here the crystal structure of the title compound.…”

trans-Bis(5,5-diphenylhydantoinato-κN3)bis(propane-1,2-diamine-κ2N,N′)nickel(II)

“…For general background see Akitsu et al (1997), Milne et al (1999). For related structures see Akitsu & Einaga et al (2005); Hu et al (2006a,b).…”

trans-Bis(2,2-diphenylethylamine-κN)bis(5,5-diphenylhydantoinato-κN3)copper(II) and its chloroform disolvate

“…In the solid state, most of these complexes afford a four-coordinated square-planar CuN 4 coordination geometry (Akitsu, Komorita & Urushiyama, 2001) with the aid of crystal-packing forces. Appropriate steric factors of the ligands can lead to a tetrahedrally distorted square-planar CuN 4 coordination geometry (Akitsu et al, 2003) or a ®ve-coordinated square-pyramidal CuN 4 O coordination geometry (Akitsu et al, 1997). To date, structural regulation by other means, such as solvent in the crystal (Tynan et al, 2004), has not been observed for analogous complexes.…”

“…The CuÐN bond distances (Table 1) are within the range found in related complexes, some of which are planar and some of which exhibit some tetrahedral distortion, viz. the CuÐN(imide) distances range from 1.975 (5) to 2.05 (1) A Ê , whereas the CuÐN(amine) distances range from 1.97 (1) to 2.030 (4) A Ê (Akitsu, Komorita & Kushi, 2001;Akitsu et al, 2003;Akitsu & Einaga, 2004). The cis-N1Ð Cu1ÐN3 angles are close to being right angles.…”