Synthesis of tetrahydrofurfurylcyclopentadiene and its thallium, manganese, and rhodium complexes and the low temperature matrix photolysis of the manganese complex

Abstract

Reaction of tetrahydrofurfuryl chloride and sodium cyclopentadienide has been found to yield tetrahydrofurfurylcyclopentadiene, I, which is converted to its thallium salt, II, by thallium ethoxide. II reacts with BrMn(CO) 5 and [ClRh(CO) 2] 2 to give the corresponding tetrahydrofurfurylcymantrene, III, and both tetrahydrofurfurylcyclopentadienyl rhodium dichloride, IV, and its dinuclear species, V. 2-D COSY analysis of the 1H NMR spectrum of V has permitted assignment of all resonances. Photolysis of the manganese complex as a Nujol solution at 77 K afforded CO ejection to give both tetrahydrofurfurylcyclopentadienylmanganesedicarbonyl, and a second isomer of this dicarbonyl species in which the pendant tetrahydrofurfuryl group was bound to the metal. Photochemical and thermal reversal of the former process gave III and more of the tetrahydrofurfuryl bound complex, while reversal of the latter process was only observed upon warming to higher temperatures. This is the first time that such an intramolecular reaction with such a remote ligand has been observed in low-temperature matrix experiments.