937255-70-4Relevant academic research and scientific papers
Trinuclear silver(I) complexes of fluorinated pyrazolates
Dias, H. V. Rasika,Palehepitiya Gamage, Chammi S.,Keltner, Jeremy,Diyabalanage, Himashinie V. K.,Omari, Ivan,Eyobo, Yvonne,Dias, Nadeeka R.,Roehr, Nathan,McKinney, Lesly,Poth, Theresa
, p. 2979 - 2987 (2007)
Silver pyrazolates {[3-(CF3)Pz]Ag}3, {[3-(CF 3),5-(CH3)Pz]Ag}3, {[3-(CF3),5-(Ph) Pz]Ag}3, {[3-(CF3),5-(But)Pz]Ag}3, and {[3-(C3F7),5-(But)Pz]Ag}3 have been synthesized by treatment of the corresponding pyrazole with a slight molar excess of silver(I) oxide. This economical and convenient route gives silver pyrazolates in high (>80%) yields. X-ray crystal structures of {[3-(CF 3),5-(CH3)Pz]Ag}3, {[3-(CF3),5- (But)Pz]Ag}3, and {[3-(C3F7),5- (But)Pz]-Ag}3 show that these molecules have trinuclear structures with essentially planar to highly distorted Ag3N 6 metallacycles. {[3-(CF3),5-(CH3)Pz]Ag} 3 forms extended columns via intertrimer argentophilic contacts (the closest Ag...Ag separation between the neighboring trimers are 3.355 and 3.426 A). The trinuclear {[3-(CF3),5-(But)Pz]Ag} 3 units crystallize in pairs, basically forming dimers of trimers , with the six silver atom core of the adjacent trimers adopting a chair conformation. However, in these dimers of trimers, even the shortest intertrimer Ag...Ag distance (3.480 A) is slightly longer than the van der Waals contact of silver (3.44 A). {[3-(C3F 7),5-(But)Pz]Ag}3, which has two bulky groups on each pyrazolyl ring, shows no close intertrimer Ag...Ag contacts (closest intertrimer Ag...Ag distance = 5.376 A). The Ag-N bond distances and the intratrimer Ag-Ag separations of the silver pyrazolates do not show much variation. However, their N-Ag-N angles are sensitive to the nature (especially, the size) of substituents on the pyrazolyl rings. The π-acidic {[3,5-(CF3)2Pz]Ag}3 and {[3-(C 3F7),5-(But)Pz]Ag}3 form adducts with the π-base toluene. X-ray data show that they adopt extended columnar structures of the type {[Ag3]2·[toluene]} ∞ and {[Ag3]′·[toluene]} ∞ ({[3,5-(CF3)2Pz]Ag}3 = [Ag3],{[3-(C3F7),5-(But)Pz]Ag} 3 = [Ag3]′), in which toluene interleaves and makes face-to-face contacts with {[3-(C3F7),5-(Bu t)Pz]Ag}3 or dimers of {[3,5-(CF3) 2Pz]Ag)3.
