Reaction of the ligand with cobalt

Reaction of the ligand with cobalt and zinc
salts, MX, (M = Co, Zn; X = C1, Br, NCS) in
ethyl alcohol led to the formation of ionic
derivatives, [M(NTB)X],[MX,], containing fivecoordinate
pseudo-trigonal bipyramidal cations
and a four-coordinate tetrahedral anion. The
blue cobalt complexes appear to be stable in
fairly dry non-aqueous solvents but on recrystallization
from aqueous acetone a series of
purple five-coordinate derivatives, [Co(NTB)-
X]X (X = C1, Br, NCS) were formed. These
trigonal bipyramidal cations could also be
stabilized as their tetraphenylborate salts by
direct synthesis from alcoholic solution. Other five-coordinate derivatives include pink cobalt
nitrate and perchlorate derivatives, [Co(NTB)-
X]X, [Co(NTB)X]BPh, (X = NO,, ClO,) and
a series of white zinc complexes, [Zn(NTB)X]-
BPh, (X = Cl, Br, I, NCS). Structural assignments
have been justified by electronic, vibrational,
and nmr spectra and by conductance and
magnetic data.