Taming Tin(IV) Polyazides

Abstract

The first charge-neutral Lewis base adducts of tin(IV) tetraazide, [Sn(N3)4(bpy)], [Sn(N3)4(phen)] and [Sn(N3)4(py)2], and the salt bis{bis(triphenylphosphine)iminium} hexa(azido)stannate [(PPN)2Sn(N3)6] (bpy = 2,2'-bipyridine; phen = 1,10-phenanthroline; py = pyridine; PPN = N(PPh3)2) have been prepared using covalent or ionic azide-transfer reagents and ligand-exchange reactions. The azides were isolated on the 0.3 to 1 g scale and characterized by IR and NMR spectroscopies, microanalytical and thermal methods and their molecular structures determined by single-crystal XRD. All complexes have a distorted octahedral Sn[N]6 coordination geometry and possess greater thermal stability than their Si and Ge homologues. The nitrogen content of the adducts of up to 44% exceed any Sn(IV) compound known hitherto.

Homoleptic Poly(nitrato) Complexes of Group 14 Stable at Ambient Conditions

“…This method is akin to the synthesis of the related hexaazido complexes. [32][33][34][35][36][37][38][39][40][41][42][43][44][45][46] The indirect approach (ii) involves the in situ formation of tetranitrates, which are then "trapped" by Lewis acid-base reactions with nitrate anions.…”

Labile Low-Valent Tin Azides: Syntheses, Structural Characterization, and Thermal Properties

“…[36][37][38] This method benefits from mild reaction conditions arising from the strong enthalpic preference for Si-F over Sn-F bonds, and from the facile removal of the gaseous TMS-F by-product. The preparation of the tetravalent tin complex Sn(N 3 ) 4 (py) 2 from SnF 4 (py = pyridine, pic = 4-picoline) 17 (1) is eventually formed if 2 is exposed to a dynamic vacuum at r.t. The analogous 4-picoline complex 3, however, is stable under these conditions.…”

“…[8][9][10] However, the kinetic stability of inorganic azides can be increased dramatically by the coordination of ancillary ligands. [11][12][13][14] The binary Lewis-acidic azides Si(N 3 ) 4 , Ge(N 3 ) 4 , Ge(N 3 ) 2 and Sn(N 3 ) 4 , for instance, have been shown to form well-defined charge-neutral adducts with Lewis bases, of the types (N 3 ) 4 E(L 2 ) (E = Si, Ge, Sn, L 2 = bpy, phen) [15][16][17] and E(N 3 ) 2 L (E = Ge, L = N-heterocyclic carbene), respectively. 18 The class of Sn(II) azides, in particular, includes monoazides Sn(N 3 )(ATI), 19 and a 1 : 1 adduct with Ag(Tp CF3 ), 20 SnN 3 (mes 2 DAP), 21 SnN 3 − 25 (see Table 1 and abbreviations in the caption).…”

Cyanidosilikate – Synthese und Struktur

“…In ersten Experimenten haben wir versucht, Salze mit dem [Si(CN) 6 ] 2− ‐Dianion zu synthetisieren, indem eine Acetonitril‐Lösung von SiCl 4 mit zwei Äquivalenten [WCC]CN und vier Äquivalenten AgCN umgesetzt wurde (Schema ; WCC=schwach koordinierendes Kation) . Alle Versuche einer vollständigen Hexa‐Substitution scheiterten, selbst bei Verwendung eines großen Überschusses beider Cyanid‐Quellen.…”