Solid State Packing and Photoreactivity of Alkali Metal Salts of trans,trans-Muconate

Abstract

Three alkali-metal salts of trans,trans-muconate (muco) viz. Li2 muco (1), Na2 muco (2), and K2 muco (3) have been prepared, and the influence of the crystal packing on the solid state photoreactivity has been investigated. Although the CC bonds of the muco ligands are oriented infinitely parallel in 1, it was found to be photoinert. In contrast, the muco ligands of 2 and 3 in the crystalline state undergo photodimerization yielding cycloocta-3,7-diene-1,2,5,6-tetracarboxylate which has been formed stepwise via the [2 + 2] cycloaddition reaction of a single pair of CC bonds and subsequent Cope rearrangement. This study demonstrates how the size of the metal ion can influence the crystal packing in metal organic salts.

Preparation of Cocrystals of 1,4‐Diimidazolylbutadiene with a Template Molecule and Dependence of the Cocrystal Photochemical Products on Wavelength

“…A possible explanation is that dimer‐1 could undergo another cycloaddition to form an unstable ladderane, and that the central cyclobutane ring of the ladderane then opens to produce dimer‐2 16. In addition, Vittal et al17 reported a similar reaction in which a cyclooctadiene derivative was produced from alkali metal salts of trans , trans ‐muconate under UV irradiation.…”

Template-Directed Photochemical [2 + 2] Cycloaddition in Crystalline Materials: A Useful Tool to Access Cyclobutane Derivatives

“…The photoproduct additionally underwent the reversible cleavage of its cyclobutane ring. Three alkali metal salts of trans , trans -muconate (muco) led to the formation of Li 2 muco, Na 2 muco, and K 2 muco, respectively . These salts underwent a [2 + 2] photodimerization and subsequent Cope rearrangements to yield cycloocta-3,7-diene-1,2,5,6-tetracarboxylate in the crystalline state.…”

“…trans , trans -Muconate (muco, 70 , Scheme ) was reacted with Na/K hydroxides to form the corresponding alkali metal salts Na/K 2 muco . These salts underwent a [2 + 2] photodimerization and subsequent Cope rearrangements to yield cycloocta-3,7-diene-1,2,5,6-tetracarboxylate 72 in the crystalline state in the crystalline (Scheme ).…”

“…Three alkali metal salts of trans,trans-muconate (muco) led to the formation of Li 2 muco, Na 2 muco, and K 2 muco, respectively. 86 These salts underwent a [2 + 2] photodimerization and subsequent Cope rearrangements to yield cycloocta-3,7-diene-1,2,5,6-tetracarboxylate in the crystalline state. Fumaric acid (45) was assembled with a linear template, 2,3-bis(4-methylenethiopyridyl)naphthalene (2,3-nap), into a 2(2,3-nap)•2(45) structure via hydrogen bond interactions (Figure 8).…”

“…trans,trans-Muconate (muco, 70, Scheme 31) was reacted with Na/K hydroxides to form the corresponding alkali metal salts Na/K 2 muco. 120 These salts underwent a [2 + 2]…”