SUPRAMOLECULAR AND METALLOSUPRAMOLECULAR COORDINATION-COMPOUNDS OF NICKEL(II) WITH THE HALF UNITS OF VICINAL OXIME-IMINE LIGANDS - MIXED-LIGAND COMPLEXES OF THE METAL-ION
Mm. Aly et Ni. Alshatti, SUPRAMOLECULAR AND METALLOSUPRAMOLECULAR COORDINATION-COMPOUNDS OF NICKEL(II) WITH THE HALF UNITS OF VICINAL OXIME-IMINE LIGANDS - MIXED-LIGAND COMPLEXES OF THE METAL-ION, Transition metal chemistry, 23(4), 1998, pp. 361-369
The [1 + 1] condensation of isonitrosoacetylacetone (Hisoacac) with o-
phenylenediamine produces the diazepine (HLBD) (1), which reacts with
Ni(OAc)(2) . 4H(2)O (1:1 molar ratio) to produce the mixed ligand comp
lex (LBDN)Ni(OAc) (2), where LBDN is the anion of the half unit obtain
ed by hydrolysis of one HLBD imine linkage. The reaction of (2) (1 mol
) with mono-, bi- and trichloroethanoic acid (1 mol) or picric acid (1
mol) led to the exchange of the acetate in (2) with the anion of the
added acid [(3)-(6), respectively]. The supramolecular structure of (2
)-(6) is achieved through the dimerization of these complexes via inte
rmolecular hydrogen bonding of the LBDN -NH2 group of one molecule and
the monodentate acetate group of another molecule. The template react
ion of o-phen with Hisoacac in the presence of Ni(OAc)(2) . 4H(2)O (1:
2:2 and 1:2:1 molar ratios, respectively) led to the formation of (LBD
N)Ni(OAc)(2)Ni(isoacac) (7) and (isophen)Ni (8), respectively; H(2)iso
phen is a symmetrical Schiff base ligand formed by the (2:1) in situ c
ondensation of Hisoacac with o-phen. The (1:1) condensation of Hisoaca
c with p-phen produced the half unit Hisopphen (9), whose 1:1 molar ra
tio reaction with Ni(OAc)(2) . 4H(2)O led to the formation of (isopphe
n)Ni(OAc) . 2H(2)O (10). The amino group of the isopphen ligand is ava
ilable for further coordination with the nickel(II) ion to produce the
metallosupramolecular complexes {[two molecules of complex (10)] [Ni(
OAc)(2)]} and {[complex (10)] [Ni(OAc)(2) . H2O]} from the 2:1 and 1:1
molar ratio reactions, respectively, of (10) with Ni(OAc)(2) . 4H(2)O
. The 1:1 molar ratio reaction of (10) with Hisoacac led to replacemen
t of OAc by isoacac. The suggested structures of the ligands and their
coordination compounds are based on analytical, chemical, spectral da
ta and magnetic moments.