A study of square-planar tellurium(II) complexes with thiourea type ligands

Te(CS(NH2)2)4SO4·2H2O: A Three-in-One Semiorganic Nonlinear Optical Crystal with an Unusual Quadrilateral (TeS4)6– Chromophore

“…The electron distribution of Te(II) in (TeS 4 ) 6− is quite unusual. The description of the electron distribution around the Te(II) atoms ends with orbital mixing model proposed by Barnard in 1981, 48 planar quadrilateral (TeS 4 ) 6− significantly contributed to the SHG effect and birefringence. Our theoretical calculations demonstrated that the prominent SHG contribution from this group was attributed to its unique electron distribution and its unequal SHG activation to CS(NH 2 ) 2 groups.…”

“…The electron distribution of Te­(II) in (TeS 4 ) 6– is quite unusual. The description of the electron distribution around the Te­(II) atoms ends with orbital mixing model proposed by Barnard in 1981, which still needs more new examples to verify.…”

“…The unique electron distribution of Te­(II) in (TeS 4 ) 6– makes the mechanism of SHG behavior of [Te­(tu) 4 ] 2+ rather distinctive. According to Barnard, the s - p z orbitals mixing can ensure the maintenance of a planar arrangement around the Te­(II) by forming two identical nonbonding electron pairs perpendicular to the p x - p y plane. The two nonbonding electron pairs can be clearly visualized by the electron localization function (ELF) diagrams (Figure a).…”