Pillaring Role of 4,4′-Azobis(pyridine)
in
Substituted Malonate-Containing Manganese(II) Complexes: Syntheses,
Crystal Structures, and Magnetic Properties
Mariadel Déniz
Irene Hernández-Rodríguez
Jorge Pasán
Oscar Fabelo
Laura Cañadillas-Delgado
Consuelo Yuste
Miguel Julve
Francesc Lloret
Catalina Ruiz-Pérez
10.1021/cg300670a.s002
https://acs.figshare.com/articles/dataset/Pillaring_Role_of_4_4_Azobis_pyridine_in_Substituted_Malonate_Containing_Manganese_II_Complexes_Syntheses_Crystal_Structures_and_Magnetic_Properties/2490529
Six new manganese(II) complexes of formulas [Mn<sub>2</sub>(Rmal)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>(azpy)]<sub><i>n</i></sub> (<b>1</b>–<b>3</b>), [Mn(Phmal)(H<sub>2</sub>O)(azpy)]<sub><i>n</i></sub> (<b>4</b>), [Mn<sub>2</sub>(Et<sub>2</sub>mal)<sub>2</sub>(H<sub>2</sub>O)<sub>4</sub>(azpy)<sub>2</sub>]<sub><i>n</i></sub> (<b>5</b>),
and [Mn(Bzmal)(H<sub>2</sub>O)<sub>3</sub>(azpy)] (<b>6</b>)
[azpy = 4,4′-azobispyridine (<b>1</b>–<b>6</b>), Rmal = methylmalonate (Memal) (<b>1</b>), dimethylmalonate
(Me<sub>2</sub>mal) (<b>2</b>), and butylmalonate (Butmal) (<b>3</b>), Phmal = phenylmalonate (<b>4</b>), Et<sub>2</sub>mal = diethylmalonate (<b>5</b>), and Bzmal = benzylmalonate
(<b>6</b>)] were synthesized and structurally characterized
by single-crystal X-ray diffraction. Complexes <b>1</b>–<b>3</b> are three-dimensional compounds whose structure consists
of corrugated layers of manganese(II) linked through <i>syn</i>–<i>anti</i> carboxylate (Rmal) bridges, which are
pillared through the bis-monodentate azpy molecule. Complex <b>4</b> has a layered structure of manganese(II) ions connected
by carboxylate (Phmal) bridges in the <i>syn</i>–<i>anti</i> coordination mode as in <b>1</b>–<b>3</b>, the azpy group acting here as a terminally bound monodentate
ligand. The structure of <b>5</b> consists of Et<sub>2</sub>mal–Mn(II) neutral chains linked through the azpy ligand,
giving rise to a complex three-dimensional network. Complex <b>6</b> is constituted by neutral [Mn(Bzmal)(H<sub>2</sub>O)<sub>3</sub>(azpy)] mononuclear units, which are interlinked through O–H···O,
O–H···N, and π–π type intermolecular
interactions to afford a three-dimensional supramolecular structure.
The topological analysis of these crystallographic structures shows
the occurrence of four different nets: a (3,4)-connected InS-type
(<b>1</b>–<b>3</b>), a binodal layered hcb (<b>4</b>), a uninodal CdS-type (<b>5</b>), and a (4,5)-connected
tcs topology (<b>6</b>). The magnetic properties of <b>1</b>–<b>5</b> were investigated in the 2.0–300 K
temperature range. Overall antiferromagnetic behavior occurs in <b>1</b>–<b>4</b> with susceptibility maxima in the
range 2.8–5.5 K, the exchange pathway being provided by the <i>syn</i>–<i>anti</i> carboxylate (substituted
malonate) bridge [manganese–manganese separation in the range
5.4365(3)–5.5274(1) Å]. Very weak antiferromagnetic interactions
are observed in <b>5</b> through the <i>trans</i>-bis-monodentate
Et<sub>2</sub>mal ligand, the intrachain manganese–manganese
separation being 7.328(3) Å. The much larger manganese–manganese
separation through the bis-monodentate azpy ligand in <b>1</b>–<b>5</b> (values greater than 13.5 Å) accounts
for the lack of any significant magnetic interaction though this extended
bridge.
2012-09-05 00:00:00
carboxylate
azpy ligand
Pillaring Role
antiferromagnetic interactions
supramolecular structure
topological analysis
susceptibility maxima
Mn
separation
Complex 4
Complex 6
Crystal Structures
Å.
Et 2mal
antiferromagnetic behavior
exchange pathway
monodentate ligand
Magnetic PropertiesSix
syn
azpy group
manganese