Nonlinear optical ASnX (A = Na, H; X = N, P) nanosheets with divalent tin lone electron pair effect by first-principles design

Divalent tin Sn2+ lone electron pairs can induce strong second harmonic generation density in 2D NaSnP and HSnN structures.

A 119Sn Mössbauer-spectroscopic characterization of the diamagnetic birefringence material Sn2B5O9Cl

The crystal structure of diamagnetic borate chloride Sn2B5O9Cl exhibits two crystallographically independent tin sites which both show pronounced lone-pair activity of the tin atoms. This is reflected in substantial quadrupole splitting in the 119Sn Mössbauer spectrum. The isomer shifts of 3.887(8) and 4.137(7) mm s−1 clearly indicate divalent tin. In agreement with bond valence calculations, the Sn1 atoms have a lower charge and the higher isomer shift, compatible with a higher electron density at the tin nuclei.