(C 5 H 12 N 2 S)Hg(NO 3 ) 2 : A Mercury Nitrate Nonlinear Optical Crystal Motivated by Heteroatom Coordination Strategy.

Effective design and synthesis of second-order nonlinear optical (NLO) materials hold immense significance in driving modern science and technology advancements. In this study, we synthesized a new acentric mercury nitrate, (C 5 H 12 N 2 S)Hg(NO 3 ) 2 , by regulating the coordination of the Hg atom through the introduction of a heteroatom. It exhibits an unprecedented [(C 5 H 12 N 2 S) 2 Hg 2 (NO 3 ) 4 ] ∞ chain composed of Hg 2+ , NO 3 - , and organic molecule C 5 H 12 N 2 S. Notably, (C 5 H 12 N 2 S)Hg(NO 3 ) 2 demonstrates an unprecedented HgO 3 S unit and a second harmonic generation (SHG) intensity of 1.3 × KDP at 1064 nm, presenting the second-order nonlinear mercury nitrate constructed by organic molecule. Theoretical calculations suggest that the HgO 3 S unit and organic molecule C 5 H 12 N 2 S significantly contribute to the SHG effect. This study demonstrates that the incorporation of heteroatoms is an effective strategy for the development of new NLO materials.