Abstract
Lanthanide complexation chemistry has been studied intensively over the past 15 years and progress has been stimulated by the advent of well-defined, kinetically robust systems tailored to applications as bioactive probes for magnetic resonance and luminescence. In this tutorial review, the extent to which an enhanced understanding of the relationship between complex structure and spectral properties is emerging is discussed, together with an examination of the mechanism of ligand exchange processes. Such issues are aiding the development of responsive probes, ranging from simple sensors to more complex studies defining water structure and exchange dynamics.