Synthesis, Structural Investigation and DFT Calculations of Cadmium (II) Fluorine-Substituted β-Diketonate: A Precursor to Producing Pure Phase Nano-Sized Cadmium (II) Oxide

Abstract

A novel aza-aromatic base adduct of a cadmium(II) fluorine-substituted b-diketonate, [Cd(dmp)(ttfa) 2 ] n (1), (''dmp'' is an abbreviation for 2,9-dimethyl-1,10-phenanthroline and ''ttfa'' is an abbreviation for thenoyltrifluoroacetonate) was synthesised and characterised by elemental analysis and IR, 1 H NMR and 13 C NMR spectroscopy and studied by thermal as well as X-ray crystallography. The single-crystal structure of this complex shows that the coordination number of the Cd 2? ion is six with two N-donor atoms from the dmp ligand and four O-donors from ttfa. Selfassembly of this complex was mediated by CHÁÁÁF-C and p-p stacking interactions. The supramolecular features of these complexes are controlled by weak directional intermolecular interactions. The structural energy of the title complex was determined by density functional theory calculations. The calculated HOMO-LUMO gap is 0.131 a.u. (3.474 eV). The CdO nano-particles were obtained by thermolysis of 1 at 180°C with oleic acid as the surfactant. Scanning electron microscopy showed that the size of the CdO particles is *35 nm.

Metal–Organic Derivatives with Fluorinated Ligands as Precursors for Inorganic Nanomaterials

“…357,358 The dimeric structure of [Ag(μ-η 2 ,η 2 -hfac)-(η 3 -diglyme)] 2 contains two silver atoms bridged by four oxygens from the two hfac ligands and a η 3 -chelating diglyme molecule on each silver atom to achieve 7-coordination number for the metal. 127 On the other hand, the tetraglyme and silylated alkyne ligands in the mononuclear complexes [Ag(hfac)(η 3 -tetraglyme)] 127 106 Mn, 370 Co, 371 Cu,105 Zn, 111,372 Cd 373 ), [M(ttac) 2 (TMEDA)] (M = Zn, 142 Ni,143 Cd 144 ), [Cd(ttac) 2 (phen)], 374 [Zn(hfac) 2 (DEA)], 111 and [Ni-(hfac) 2 (pda)] 110 have been isolated and employed as excellent CVD precursors. In these cases, the enhanced Lewis acidity of the metal center due to the presence of fluorinated groups enables it to bind to the ancillary diamine ligand, yielding stable six-coordinated M(II) complexes with MO 4 N 2 environment around the metals.…”

“…Divalent Metals. In the presence of coordinating donor molecules, the homoleptic [M(β-dik F ) 2 ] compounds instantly coordinate them to afford higher coordinated solvated species such as [M(hfac) 2 (L) 2 ] [M = Cr, 315 Mn, 83,316 Co, 361 complexes with chelating diamine ligands such as [M-(hfac) 2 (TMEDA)] (M = Fe, 106 Mn, 370 Co, 371 Cu, 105 Zn, 111,372 Cd 373 ), [M(ttac) 2 (TMEDA)] (M = Zn, 142 Ni, 143 Cd 144 ), [Cd(ttac) 2 (phen)], 374 [Zn(hfac) 2 (DEA)], 111 and [Ni-(hfac) 2 (pda)] 110 have been isolated and employed as excellent CVD precursors. In these cases, the enhanced Lewis acidity of the metal center due to the presence of fluorinated groups enables it to bind to the ancillary diamine ligand, yielding stable six-coordinated M(II) complexes with MO 4 N 2 environment around the metals.…”

“…In the presence of coordinating donor molecules, the homoleptic [M­(β-dik F ) 2 ] compounds instantly coordinate them to afford higher coordinated solvated species such as [M­(hfac) 2 (L) 2 ] [M = Cr, Mn, , Co, Cd (L = THF, py, OCMe 2 , or H 2 O)], [Cu­(ptac) 2 (EtOH)] and [Cu­(hfac) 2 (L)] (L = Bu t NH 2 , 2-ethynylpyridine), , [Cu­(β-dik F ) 2 (L) 2 ] (L = PPh 3 , imidazole, H 2 O), , [M­(hfac) 2 (M 3 PO)] 2 (M = Mn, Co, Ni; M 3 PO = 2,5,5-trimethyl-1-pyrroline- N -oxide), [M­(hfac)­(2-PyBN) 2 ]­[M­(hfac) 3 ] (M = Mn, Co, Ni, Fe; 2-PyBN = N - tert -butyl-R-(2-pyridyl)­nitrone), [Cu­(hfac) 2 (2-pyBN)], and [{Cu­(hfac) 2 (H 2 O)} 2 (μ-tetracyanoethylene)] . While the majority of these complexes are expectedly octahedral, a few of them are stabilized even in lower coordination number and have interesting structure; for example, the square planar structure of [Pd­(hfac-C)­(hfac-O,O)­(L)] (L = SEt 2 , HNMe 2 , 2,6-Me 2 py, phenoxathiin, phenazine) has one carbon-bonded hfac ligands. − A number of transition metal-hfac complexes with chelating diamine ligands such as [M­(hfac) 2 (TMEDA)] (M = Fe, Mn, Co, Cu, Zn, , Cd), [M­(ttac) 2 (TMEDA)] (M = Zn, Ni, Cd), [Cd­(ttac) 2 (phen)], [Zn­(hfac) 2 (DEA)], and [Ni­(hfac) 2 (pda)] have been isolated and employed as excellent CVD precursors. In these cases, the enhanced Lewis acidity of the metal center due to the presence of fluorinated groups enables it to bind to the ancillary diamine ligand, yielding stable six-coordinated M­(II) complexes with MO 4 N 2 environment around the metals.…”