Complexes of silver(II) and silver(III) with macrocyclic tetraaza ligands

Abstract

Silver(II) complexes of four macrocyclic tetraaza ligands have been prepared by disproportionation of Ag(I) in the presence of the ligand. Some of these complexes may be oxidized to silver(III) species electrochemically or with NO* salts. Spectral and electrochemical properties of the new compounds are reported.

Structure, Magnetic Properties and Magnetic Phase Diagram of a Layered, Bimetallic, Cyanide-Bridged CrIII-NiII Metamagnet

“…The [Ni(tmc)](ClO 4 ) 2 salt was prepared as previously reported. [47] The powder samples of the reported compound were obtained as follows: an aqueous solution ( General Remarks: Thermogravimetric studies were carried out in argon atmosphere at a heating rate of 1°C per minute. The magnetic measurements were performed using a SQUID magnetometer operating in the 300Ϫ2 K temperature range and the 0Ϫ55 kOe magnetic field range.…”

The theory-driven quest for a novel family of superconductors: fluorides

“…132 Ag(II) binds to the lone pair of a covalently bound N, as seen in various complexes of Ag 2+ with pyridine, pyrazine, a,a 0 -bipirydyl or tripirydyl 133 and with permethylated cyclam. 134 Compounds with Ag-N and Ag-O bonds have also been synthesized as exemplified by complexes of Ag(II) with 2-carboxypirydyl acid and the anion of nicotinic acid. Strong complexation allows for reduction of the standard redox potential for the Ag(II)/Ag(I) pair down to 1.453 V, 132 so synthesis may be performed even in aqueous solutions, using K 2 S 2 O 8 , PbO 2 , CeO 2 or BaO 2 as oxidizers.…”

The reduction of Ag(I) by α‐silylamines R2NCH2SiX3

“…41 The complexes of macrocyclic amines [5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane (L) and related compounds] with Ag(I) are stable in dry acetonitrile, but in aqueous-methanol solution they disproportionated under formation of Ag(II)L complexes and silver metal. 42,43 The compounds X-CH 2 -M with heteroatoms X = O, S or N in geminal position relative to a group 14 element (M = Si, Ge, Sn) often show unusual reactivity and exhibit unexpected spectroscopic properties. 44 -49 The nature of this α-effect has been described with various models of orbital interaction.…”