• Sanii, Rana
• Bajpai, Alankriti
• Patyk-Kaźmierczak, Ewa
• Zaworotko, Michael J.

Abstract

Solid-state synthesis (S3) is an attractive approach to organic synthesis as in principle it offers minimal solvent waste and high yield. However, many functional groups are ill-suited for S3 reactions, which tend to only proceed when substrates are aligned in the solid-state according to the topochemical principle. The aim of this work is to use high yield, low-waste synthetic methods to develop a library of novel Schiff bases that can be utilized as linker ligands to prepare coordination networks. Herein, we report that eight pyridyl- and/or imidazolyl-substituted Schiff bases, 1–8, five of which are new chemical entities, can be prepared via reaction of an amine and an aldehyde without the use of solvent. All eight compounds were prepared via solvent-drop grinding (SDG) in multigram scale in >95% yield and each was characterized by FTIR, 1H and 13C NMR spectroscopies and single crystal X-ray diffraction. One of the aldehydes used is a liquid under ambient conditions so its reactions to form 1–4 are not classified as S3 reactions whereas the other aldehydes are solids and 5–8 are therefore S3 reactions. The SDG solvents were selected in accordance with guidelines used by industry. 1–4 were also prepared quantitatively via addition of the liquid aldehyde (4-pyridinecarboxaldehyde) to a solution of the corresponding amine. That 1–8 contain functional groups suitable for coordinating with metal cations will enable 1–8 to serve as linker ligands in coordination networks as exemplified by 5, which forms a parallel interpenetrated coordination network with square lattice, sql, topology

Topics

• impedance spectroscopy
• compound
• single crystal X-ray diffraction
• single crystal
• grinding
• Nuclear Magnetic Resonance spectroscopy
• amine
• aligned
• aldehyde