Reaktivität von Magnesium-und calcium-bis[bis(trimethylsilyl) phosphanid] gegenüber bis[bis(trimethylsilyl) amino]stannylen in Toluollösung

Abstract

The metathesis reaction of magnesium bis[bis(trimethylsilyl)phosphanide] and bis[bis(trimethylsilyl)arsanide] with bis[bis(trimethylsilyl)amino]stannylene yields the dimeric bis[bis(trimethylsilyl)phosphanyl]stannylene and bis[bis(trimethylsilyl)arsanyl]stannylene respectively. The red arsenic derivative crystallizes as a cis isomer in the orthorhombic space group P2 12 12 1 with a = 1316.4(2), b = 1834.3(2), c = 2054.9(4)pm and Z = 4 dimers. The central moiety is the folded Sn 2As 2 cycle with SnAs bond lengths of 276 pm. The exocyclic SnAs distances are 6 pm shorter. In contrast with this reaction, calcium bis[bis(trimethylsilyl)phosphanide] forms with bis(bis(trimethylsilyl)amino]stannylene in toluene the three-nuclear heterometallic complex (Me 3Si) 2NCa[μ-P(SiMe3) 2] 2Ca[μ-P(SiMe 3) 2] 2SnP(SiMe 3) 2, which crystallizes in the monoclinic space group P 2 1 c with a = 1935.1(3), b = 2028.8(3), c = 1880.1(3) pm, β = 96.53(1)° and Z = 4. The CaP bond lengths lie in the area of 289 pm; the terminal CaN distance reveals an extraordinarily small value with 222 pm.