Carbon-13 nuclear magnetic resonance study of tricarbonyldieneiron complexes: Substituent effects in relation to π-bond orderdistributions

Abstract

The changes in ¹³C shieldings of C 1 and C 3, produced by methoxyl and methoxycarbonyl substituents at C 2, reflect the distribution of π-bond orders in uncomplexed 1,3-dienes, and indicate a substantial reorganization of this distribution upon forming diene-Fe(CO)₃ complexes.