Synthesis, crystal structure and characterization of 3-thiophene aldehyde thiosemicarbazone and its complexes with cobalt(II), nickel(II) and copper(II)

Abstract

The reaction of cobalt(II), nickel(II), copper(II) chlorides and bromides with 3-thiophene aldehyde thiosemicarbazone (3TTSCH) leads to the formation of a series of new complexes:2 , [CuBr(3TTSC)] 2 and [CuBr 2 (3TTSCH)]. The crystal structures of the free ligand and of the compound [Ni(3TTSC) 2 ] have been determined by X-ray diffraction methods. For all these complexes, the central ion is coordinated through the sulfur and the azomethine nitrogen atom of the thiosemicarbazone. [Co(3TTSC) 2 ], [Ni(3TTSC) 2 ] and [CuBr 2 (3TTSCH)] are mononuclear species, while [CuCl(3TTSC)] 2 and [CuBr(3TTSC)] 2 are binuclear complexes.

Molecular structures and spectroscopic characterization of cobalt(III) and nickel(II) complexes of N-(2-hydroxyethyl)-2-(thiophene-2-ylmethylene)-hydrazinecarbothioamide

“…The C5-N1 and C6-N2 bond distances are typical for double-bonded Schiff base compounds [17]. The mean Ni1-N1 and Ni1-S1 bond distances are 1.906(2) and 2.1763(6) Å , respectively, which agree with those found in the Cambridge Structural Database for square planar thiosemicarbazone nickel(II) complexes (Ni1-N1 1.84-1.93 Å and Ni1-S1 2.09-2.18 Å ) and compare well with those of other square planar nickel(II) complexes with similar ligands [17,18,20,35].…”

“…The C6-S1 bond length is 1.739(2) Å , which is shorter than 1.82 Å for a C-S bond and longer than 1.56 Å for a C-S bond [28,29], supporting the suggestion that the complex formation involves the ligand in its thiol form. Further, this bond length is longer than that of a typical C-S double bond found in free thiosemicarbazones e.g., 1.687(3) Å in 3-thiophenealdehyde thiosemicarbazone [20], 1.704(5) Å in ferrocene-1-carbaldehyde thiosemicarbazone [32], 1.704(3) Å 4-methylbenzaldehyde thiosemicarbazone [33] and 1.693(2) Å in (E)-4-octyloxybenzaldehyde thiosemicarbazone [34], which is another evidence for the thiolate form in the complex. The C5-N1 and C6-N2 bond distances are typical for double-bonded Schiff base compounds [17].…”

“…In recent years, some structural and spectral studies on thiophene-derived thiosemicarbazones have been undertaken [15][16][17][18][19][20].…”

Synthesis, spectroscopic characterization, crystal structures, and theoretical studies of (E)-2-(2,4-dimethoxybenzylidene)thiosemicarbazone and (E)-2-(2,5-dimethoxybenzylidene)thiosemicarbazone

“…They have been evaluated over the last 50 years as antiviral, antibacterial, and anticancer therapeutics, and biological activities of them are a function of parent aldehyde or ketone moiety [2][3][4][5][6][7]. Thiosemicarbazone is an important group of multidentate ligands and usually coordinates with the metal through the imine nitrogen and sulfur atom [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] (Scheme 1).…”

Diorganotin(IV) complexes of 3,5-dichloro-2-hydroxybenzaldehyde-N(4)-ethylthiosemicarbazone: Synthesis, spectral characterization and crystal structure

“…Thiosemicarbazones and their metal complexes are important series of compounds due to their potential biological activity as antifungals, anti-virals, anti-malarials and anti-tumour agents [7][8][9][10][11][12][13][14]. In particular, transition metal complexes with substituted thiosemicarbazones have received much attention due to their coordination chemistry and potential biological activity [15][16][17][18][19][20][21][22]. The N(4)-substituted thiosemicarbazones and their metal complexes exhibit significant biological activities which vary from those of either metal atom or parent ligands [23][24][25][26][27].…”