A triplet biradical organocalcium species derived from partial oxygen quenching of a substituted cyclopentadienyl calcium compound
Abstract
Reaction of [Ca{C5H3-1,3-(SiMe3)2}2]1, in toluene with oxygen yields the stable, rigid biradical [Ca{η-C5H3-1,3-(SiMe3)2}{µ-OC5H2-2,4-(SiMe3)2}]22, characterised by an X-ray structure determination [Ca–O 2.298(3), 2.210(3)Å; Ca–centroid 2.374(–)°; Ca–O–Ca 105.4(1)°; O–Ca–centroid 149.4(–)°] and EPR spectroscopy (resonance at g= 9.01, 4.21, 3.87 result from a super-exchange interaction between two unpaired electrons in the biradical).