HgBrI: a possible tecton for NLO molecular materials?

Area of Science:

• Materials Science
• Solid-State Chemistry
• Optoelectronics

Background:

• Mixed mercury(II) halogenides are established non-linear optic (NLO) materials.
• NLO properties depend on halogen arrangement and electronic structure in soft element bonds.

Purpose of the Study:

• Investigate HgBrI as an asymmetric tecton for noncentrosymmetric crystalline compounds.
• Explore the coordinating ability of Hg(II) with N-donor ligands to synthesize new complexes.

Main Methods:

• Synthesis of seven coordination complexes.
• Characterization using Raman spectroscopy, single-crystal X-ray diffraction (SC-XRD), and Second Harmonic Generation (SHG) measurements.
• Periodic Density Functional Theory (DFT) computational analysis.

Main Results:

• Obtained seven coordination complexes utilizing HgBrI.
• Identified substitutional disorder in low-symmetry HgBrI crystalline products.
• Disorder leads to the absence of an inversion center, conferring NLO activity.
• NLO activity was absent in analogous Hg(II) halide complexes.

Conclusions:

• HgBrI serves as an effective tecton for creating metallorganic NLO materials.
• Substitutional disorder in HgBrI crystals is key to achieving NLO properties.
• This approach offers a pathway to novel noncentrosymmetric NLO materials.