Photochemische reduktivetrans-Eliminierung beitrans-Diazidotetracyanoplatinat(IV)

Abstract

Das neue Reagens ( 2 ) ergibt rnit Elektrophilen die in Tabelle 1 zusammengestellten Produkte (3) und ( 4 a ) . Die mit Carbonylverbindungen erhaltenen Diole (3 d)-(3 g) cyclisieren rnit Salz~aure/Ether[~~ zu den Dihydroisobenzofuranen ( 4 b)-(4e) (Tabelle 1, unten).

Photochemical Reductive trans-Elimination from trans-Diacidotetracyanoplatinate(IV) Complexes

“…These signals, which were most clearly seen for [Pt (CN) 4 (N3)2] 2~ [1], are characteristic for N-atoms. The ESR spectrum shows a well resolved 1:1:1 triplet with g = 2.0026 and a hyperfine coupling of 5.1 G. These data correlate with those given by Symons [8][9][10] for irradiated sodium azide.…”

“…2~ and two azide radicals [1]. While in aqueous solution the azide radicals yield only molecular nitrogen, in ethanol they are also able to abstract hydrogen atoms from the solvent with formation of CH3CHOH radicals and HN3.…”

Photochemical oxidative addition of hydrazinium cations to tetracyanoplatinate(II) induced by OSCT excitation

“…In addition, interconversions between hydrazine and ammonia play an important role in nitrogen fixation [6,7]. In the context of the present study it should be noted that photochemical reductive eliminations of [Pt IV (CN) 4 X 2 ] 2À with X À = halide and azide initiated by LMCT excitation are well known to yield [Pt II (CN) 4 ] 2À [8,9]. 4 ] 2À is photochemically and thermally very stable in solution [8,9] and displays a characteristic absorption spectrum with k max = 278 (e = 1600 M À1 cm À1 ), 254 (12 300), 239 (sh, 1800) and 215 (22 500) nm.…”

“…In the context of the present study it should be noted that photochemical reductive eliminations of [Pt IV (CN) 4 X 2 ] 2À with X À = halide and azide initiated by LMCT excitation are well known to yield [Pt II (CN) 4 ] 2À [8,9]. 4 ] 2À is photochemically and thermally very stable in solution [8,9] and displays a characteristic absorption spectrum with k max = 278 (e = 1600 M À1 cm À1 ), 254 (12 300), 239 (sh, 1800) and 215 (22 500) nm. Addition of diluted acids does not change this spectrum nor does it affect the thermal or photochemical stability of [Pt(CN) 4 ] 2À .…”

Schlüssel zum Öffnen photolabiler, metallhaltiger Käfige

“…Durch Einstrahlung in die LMCT-Bande des Komplexes wurde eine reduktive Eliminierung bewirkt. [62,63] Die Iodid-Abgangsgruppe wird zu einem Radikal oxidiert, und es entsteht Pt -Spezies photoreduziert. Der Mechanismus der Photoreduktion ähnelt dem oben beschriebenen, außer dass sich die Azidradikale schnell zu molekularem Stickstoff zersetzen und so die Reoxidation des Platinzentrums verhindert wird.…”