Weak paramagnetism in compounds of the type Cp′2Yb(bipy)

Measuring the magnetic moments of solids that are air and moisture sensitive is difficult, particularly when the net magnetic moments are small, as is the case for the organometallic compounds described here. The use of quartz tubes to contain the compounds has been developed and applied to substituted ytterbocene bipyridine complexes, some of which were previously reported as diamagnetic. The SQUID measurements quantify the extent of paramagnetism and they correlate with the qualitative variable temperature 1H NMR spectra.