Miscellaneous Complexes of Cobalt

X-Ray analysis of a green compound originally formulated as [CoClj-(bipy)JCl has established that the correct formulation is c y-[CoCU(bipy)al8-[CoCy with an octahedral cobalt(iu) cation and a tetrahedral cobalt(n) anion. The Co -Q and Co -Q distances are respectively 2.23 and 2.38 A. The bipyiidyl ligands are twisted slightly so that the average angle between the pyridine rings is 5°.  

In tte dioxygen complex (SO) the co-ordination at the cobalt atom is trigonal bipyramidal, one of the equatorial positions being occupied by the midpoint of the 0-0 vector. The Co-P distances ran from 2.232(3) to 

251(3) A. The Co-O distances of 1.871(7) and 1.902(7) A are not significantly different and the 0-0 distance is 1,420(10) A. Distorted trigonal-bipyramidal co-ordination at the cobalt atom is found in the molecular structure of hydridotetrakis(diethyl phenylphosphonite)cobalt(i), HCo[PhP-(OEt)2l4. The cobalt atom is displaced by 0.492 A from the plane of the three equatorial phosphorus atoms towards the axial phosphorus atom the Co-P(axial) distance of 2.128(1) A agrees well with the Co-P(equatorial) distances of 2.126(1), 2.103(2), and 2.115(2) A. The hydridic hydrogen atom was located at 1.54 A from the metal in a difference map after least-squares refinement the Co-H distance was 1.38(54) A.  

The structures of the complexes [Co L]BF and [Co L], where L is the cage ligand [CiaHisNsOsBsFa] - (51), have been described the mean Co N and Co -N distances are 1.893(4) and 1.973(2) A the distances and angles within the ligand do not differ significantly in the two complexes. The symmetry of the cobalt(iii) complex is close to and the metal co-ordination 

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