A Non-Football Cage Type Dodecanuclear Organostannoxane: Synthesis, Structure and NDR Behavior

A new dodecanuclear organostannoxane with an unprecedented structure comprising four O-capped clusters is isolated using 2-(phenylazo)phenyl substitution on the tin center. The formation of [(RSn)12(µ3-O)4(µ2-O)3(µ2-OH)21] [Cl]·5PhCH3·THF (1) is achieved by the complete hydrolysis of RSnCl3 [R = 2-(phenylazo)phenyl] in the presence of excess sodium hydroxide in refluxing ethanol/water (1:1) mixture. Complex 1 crystallizes in the triclinic space group P-1. The absence of N→Sn intramolecular coordination in the molecular structure of 1 illustrates the hemi-labile nature of N→Sn intramolecular coordination. Each tin atom in complex 1 is hexacoordinated, possessing distorted octahedral geometry. All the 12 Sn centers in complex 1 are held together through four µ3-O2− three µ2-O2−, and twenty-one µ2-OH− ligands resulting in the formation of a central Sn12 oxo-hydroxo core having four o-capped clusters in the framework. I-V characteristic curve of complex 1 based device displayed an interesting negative differential resistance (NDR) behavior in the voltage range of 1.0–1.8 V with excellent repeatability of 200 cycles.