Abstract
The title compound [Ni(4-NH
2-C
6H
4CO
2)
2(CH
3OH)
2]
·
CH
3OH (
1) consists of Ni(II) atoms doubly bridged by
p-aminobenzoate ligands (PAB) into 1D chains which are further connected into a 3D framework by methanol molecules through hydrogen bonding. Intrachain π–π interactions are observed between the aromatic rings of doubly bridging PAB. The magnetic data of compound
1 for the temperature range 300–3
K is indicative of ferromagnetically coupled nickel species. Thermogravimetric analysis of
1 indicates a sharp weight loss of one PAB ligand and two coordinated methanol molecules. The formation constant and thermodynamic parameters of complexation of Ni(II) with
p-aminobenzoic acid have been evaluated.
The title compound [Ni(4-NH
2-C
6H
4CO
2)
2(CH
3OH)
2]
·
CH
3OH (
1) consists of Ni(II) atoms doubly bridged by
p-aminobenzoate ligands (PAB) into 1D chains which are further connected into a 3D framework by methanol molecules through hydrogen bonding. Compound
1 is monoclinic
P2(1)/
n,
a
=
9.0903(5)
Å,
b
=
10.9059(5)
Å,
c
=
9.9994(5)
Å,
β
=
106.6880(10)°,
Z
=
4. Intrachain π–π interactions are observed between the aromatic rings of doubly bridging PAB ligands. The aromatic rings are in an offset arrangement with 3.607
Å interplanar spacing. The magnetic data of compound
1 for the temperature range 300–3
K is indicative of ferromagnetically coupled nickel species. The best fitting parameters were obtained for
J
=
0.74
cm
−1,
D
=
−2.48
cm
−1 and
g
=
2.35. Thermogravimetric analysis of
1 indicates a sharp weight loss of one PAB ligand centered at 387.42
°C (Δ
H
=
94.86
kJ/mol) and a loss of two coordinated methanol molecules at 489.20
°C with Δ
H
=
29.78
kJ/mol. The formation constant of Ni(II) with
p-aminobenzoic acid has been evaluated at different temperatures using pH titration techniques in 50% ethanol. The obtained values at 25
°C are log
K
f1
=
3.24 and log
K
f2
=
1.21. The thermodynamic parameters of complexation were also calculated and discussed.