Four novel trinuclear copper(II)/nickel(II) complexes wit
h four trianionic pentadentate ligands,
N-(3-
t-butylbenzoyl)-5-nitrosalicyl
hydrazide (H
33-
t-bbzns
hz),
N-(3,5-dimet
hylbenzoyl)salicyl
hydrazide (H
33,5-dmbzs
hz),
N-(p
henylacetyl)-5-bromosalicyl
hydrazide (H
3pabs
hz) and
N-(3-
t-butylbenzoyl)salicyl
hydrazide (H
33-
t-bbzs
hz)
have been synt
hesized and c
haracterized by X-ray crystallograp
hy. T
hese trinuclear compounds all
have an M–N–N–M–N–N–M core formed by t
hree metal ions and two ligands. T
he geometries of t
hree Cu(II) ions in compound Cu
3(3-
t-bbzns
hz)
2(H
2O)(DMF)(py)
2 · DMF (
1) alternate between distorted square pyramidal and square planar, w
hile in compound Cu
3(3,5-dmbzs
hz)
2(py)
2 (
2), t
hey are all square planar. T
hree Ni(II) ions in compound Ni
3(pabs
hz)
2(DMF)
2(py)
2 (
3) and Ni
3(3-
t-bbzs
hz)
2(py)
4 · 2H
2O (
4) follow square-planar/octa
hedral/square-planar coordination geometry. Compounds
1,
2 and
4 are bent trinuclear, wit
h t
he bend angles of 156.4°, 141.49° and 127.1°, respectively, w
hile t
he t
hree nickel ions in compound
3 are strictly linear, wit
h an angle of 180°. Studies on t
he trinuclear Ni(II) complexes s
how t
hat t
he β-branc
hed
N-acylsalicyl
hydrazide ligands wit
h sterically flexible C
http://www.sciencedirect.com/scidirimg/entities/204e.gif"" alt=""greek small letter alp
ha"" title=""greek small letter alp
ha"" border=""0""> met
hylene groups are easier to yield linear trinuclear Ni(II) complexes, w
hile
http://www.sciencedirect.com/scidirimg/entities/204e.gif"" alt=""greek small letter alp
ha"" title=""greek small letter alp
ha"" border=""0"">-branc
hed
N-acylsalicyl
hydrazides ligands tend to form bent trinuclear Ni(II) complexes. Antibacterial screening data indicate t
hat t
he trinuclear Cu(II) compound
2 is more active t
han
1 and mononuclear Cu(II) compound, bent trinuclear Ni(II) compound
4 is more active t
han linear compound
3 and less active t
han tetranuclear nickel compound in t
he previous study.