The crystal structure and chemistry of the "red salt" α-trisilver-amidoselenate, Ag₃NSeO₃

Abstract

The crystal structure of the a-modification of the "red salt" of trisilver amidoselenate, Ag3NSe03 has been determined from MoKa X-ray diffraction data, and refined to R = 3.19% from 337 unique absorption-corre~ted observed reflections. The structure is rhombohedral, R3c (No. 161), with (hexagonal) a = 8.462(4), c = 11.372(6) A. The formula unit has point symmetry 3 (C3), with Se and N on the threefold axis, each approximately tetrahedrally coordinated; Se by tkee oxygen atoms (at 1.651(8) A) and N (at 1.70(2) A), and N by Se and three silver atoms (at 2.164 (8) IntroductionThe formation of an orange-red precipitate, during the reaction of ammonium amidoselenate NH4Se03NH2 with silver nitrate in dilute NH40H, was first observed by Dostal and KrejEi (1) in 1958. Later, Engelbrecht and Clementi (2) described this reaction in their work on Se-N compounds. They suggested that the formation of the title compound most probably proceeds via substitution of the amino-group hydrogens by silver. Further studies of the compounds of the type Ag-N-X (where X is S or Se) were carried out by Dostal and RdiiEka (3), RdiiEka (4), and Paetzold, Dostal, and RdiiEka (5). It was Dostal and RdiiEka (3) who first confirmed the existence of two different modifications of Ag3NSe03, and named them a and P. The a-modification results from the reaction given in ref. 3, while the P-modification results when the orange-red precipitate is kept at room temperature in the mother liquor for several days. The p-form can also be obtained as a product of the hydrolysis of Ag3NSe03. 3NH3. 2H20. Both modifications are highly explosive, and can be distinguished easily by their different X-ray powder patterns.Paetzold, Riiiitka, and Dosthl (5) studied a number of silver compounds containing NX03 groups (X = S, Se) by means of IR spectroscopy. They proposed possible structural models for

Synthesis of Luminescent Trinuclear Silver(I) Acetylides of Bis(diphenylphosphino)methane and Bis(diphenylphosphino)-n-propylamine. X-ray Crystal Structures of [Ag3(μ-dppm)3(μ3-η1-C⋮C-C6H4-NO2-p)]2+ and [Ag3(μ-dppm)3(μ3-η1-C⋮C-C6H4-NO2-p)2]+

“…A similar bonding mode has been observed in the related trinuclear copper(I) acetylide complexes. 6a,d, Monocapped triangular silver(I) complexes are scarce. An example of such a bonding mode in trinuclear silver(I) is the monomer of the α-trisilver amidoselenate polymeric networkAg 3 NSeO 3 where the O 3 SeN 3 - group is monocapped to three silver metal centers 6a,d, complex 4 represents the first example of a monocapped trinuclear silver(I) acetylide complex.…”

Structure of potassium amidoselenate K+.SeO3NH2−

“…Although no X-ray structure determinations of simple amidoselenates are known, the structures of K3(NSeO3) 3 (Kocman & Rucklidge, 1974), Ag3SeO3N (Kocman & Szymanski, 1990) and Ag3SeO3N.3NH3.2H20 (#.~k, Rf~i6ka & Glowiak, 1991) have been reported. The chemistry of Se vI Beq = 8~--~-~i~jUua*a~ai.ay.…”

The crystal structure of the "White Salt" trisilver(I) amidoselenate-3-ammonia-2-water [Ag(NH3)2]Ag2SeO3N•3NH3•2H2O

“…The deep-red a-modification (the "red salt") is formed when the amorphous precipitate is boiled in the mother liquor for a few minutes, the light-red P-modification results if the precipitate is allowed to stay in the mother liquor at room temperature for some time (2,3). The crystal structure of the "red salt" has already been determined (4,5). Both a and P modifications dissolve easily in dilute water solution (1%) of ammonia and after a few hours of standing at room temperature, colourless needles of the "white salt" Ag3Se03N.3NH3.2H20 crystallize from the solution.…”