Combining polarized low-frequency Raman with XRD to identify directional structural motifs in a pyrolysis precursor

Abstract

Long–range structures and dynamics are central to coordination chemistry, yet are hard to identify experimentally. By combining polarized low-frequency Raman spectroscopy with single crystal XRD to study barium nitrilotriacetate, a metal–organic coordination polymer and a useful pyrolysis precursor, we could assign Raman peaks experimentally to layer shear motions and perpendicular hydrogen bond vibrations. These directional long–range interactions further determined the preferred fracture directions during crystallization, establishing an important link between structural motifs in the precursor, and the porosity of the carbon it yields upon pyrolysis.