Small chains of main group elements by BH3 adduct formation of tBu2E-N(H)-EtBu2 (E = P, As)

Abstract

Borane adducts of bis(di-tert-butylphosphanyl)amine (1a) and bis(di-tert-butylarsino)amine (1b) are reported. Based on quantum-chemical investigations in combination with experimental results, it is demonstrated that the tautomerism known for tBu2P-N(H)-PtBu2 (1a), can be observed for the mono adduct tBu2P-N(H)-P(BH3)tBu2 (2a) as well, whereas for the corresponding arsenic compound 2b only one stable isomer is found. The bis-borane adduct tBu2(BH3)As-N(H)-As(BH3)tBu2 (3b) is a rare example of a structurally characterized, tertiary arsine borane adduct, which can be directly compared with the corresponding phosphorus compound tBu2(BH3)P-N(H)-P(BH3)tBu2 (3a). Deprotonation of mixtures containing 2a by nBuLi leads to the lithium-containing coordination polymer 4a, in which the actual chain consists only of non-carbon atoms.