Azido- and thiocyanato-cobalt(II) complexes based pyrazole ligands

Five-coordinate metal(II) complexes based pyrazolyl ligands

“…Electronic spectra were recorded using Agilent 8453 HP diode UV-Vis spectrophotometer. 1 H and 13 C NMR spectra were obtained at room temperature on a Bruker 400 MHz NMR spectrometer operating at 400 MHz ( 1 H) and 100 MHz ( 13 C). 1 H and 13 C NMR chemical shifts (d) 1, 128.4, 138.5 (phenyl carbons), 104.4, 139.2, 145.6 (pz-carbons).…”

“…The ambidentate nature of the thiocyanate anion NCS À , together with the azide ion, N 3 À and the ability of these ligands to bridge and assemble metal ions in extended network structures made these ligands to be among the most extensively studied species [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. The interaction of NCS À and N 3 À with divalent metal ions have led to the construction of polynuclear and coordination polymers of diverse topology [1][2][3][4][5]7,[10][11][12][13][14][15][16][17][18] and the development of new magnetic molecular materials of different bridging-azido, and -thiocyanato bonding modes [2,3,4b,5,7,10-17].…”

“…The interaction of NCS À and N 3 À with divalent metal ions have led to the construction of polynuclear and coordination polymers of diverse topology [1][2][3][4][5]7,[10][11][12][13][14][15][16][17][18] and the development of new magnetic molecular materials of different bridging-azido, and -thiocyanato bonding modes [2,3,4b,5,7,10-17]. These modes have been recently summarized and addressed [3,4,14,15].…”

“…In general, many bridging thiocyanato-and azido-complexes are produced when the coordinated coligand(s) is mono-, bi-, tri-or linear tetra-dentate [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. This may result from the tendency of the metal ion to attain its favorite geometry through the enforcement of the SCN À or N 3 À ion to act as a bridging ligand.…”

Synthesis, Structures and Properties of Cobalt Thiocyanate Coordination Compounds with 4-(hydroxymethyl)pyridine as Co-ligand

“…Compounds that consist of paramagnetic metal cations are of particular interest because they can show different magnetic properties and thus it is not surprising that an increasing number of new compounds were recently reported [5][6][7][8][9][10][11][12][13][14]. One group of these compounds are transition metal thiocyanato coordination polymers, which show a variety of different coordination modes including the terminal and the bridging coordination, with the latter being of special importance because cooperative magnetic properties can be expected [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34]. This is one reason why we are especially interested in thio-and selenocyanato coordination polymers, in which the metal centers are connected into chains by pairs of µ-1,3-bridging anionic ligands [35][36][37][38][39][40][41][42][43][44][45][46][47].…”