cis-Bis(2,2′-bipyrimidine-κ2 N 1,N 1′)diiodidomanganese(II)

The asymmetric unit of the title complex, [MnI2(C8H6N4)2], contains one half of a neutral MnII complex, with the entire molecule completed by the application of twofold symmetry. The MnII ion is six-coordinated in a distorted octahedral environment defined by four N atoms of the two chelating 2,2′-bipyrimidine (bpym) ligands and two I− anions in a cis-N4I2 coordination geometry. The dihedral angle between the least-squares planes of the two bpym ligands (r.m.s deviation for all non-H atoms = 0.063 Å) is 85.04 (6)°. In the crystal, complex molecules are connected by C—H⋯N and C—H⋯I hydrogen bonds, forming a three-dimensional network. Molecules are stacked in columns along the a axis. Along the c axis, successive molecules stack in the opposite directions.

The asymmetric unit of the title complex, [MnI 2 (C 8 H 6 N 4 ) 2 ], contains one half of a neutral Mn II complex, with the entire molecule completed by the application of twofold symmetry. The Mn II ion is six-coordinated in a distorted octahedral environment defined by four N atoms of the two chelating 2,2 0bipyrimidine (bpym) ligands and two I À anions in a cis-N 4 I 2 coordination geometry. The dihedral angle between the leastsquares planes of the two bpym ligands (r.m.s deviation for all non-H atoms = 0.063 Å ) is 85.04 (6) . In the crystal, complex molecules are connected by C-HÁ Á ÁN and C-HÁ Á ÁI hydrogen bonds, forming a three-dimensional network. Molecules are stacked in columns along the a axis. Along the c axis, successive molecules stack in the opposite directions.

Comment
The asymmetric unit of the title complex, [MnI 2 (bpym) 2 ] (bpym = 2,2'-bipyrimidine, C 8 H 6 N 4 ), contains one half of a neutral Mn II complex (Fig. 1). The complex is disposed about a twofold rotation axis running in the [010] direction passing through the Mn1 atom. The Mn II ion is six-coordinated in a distorted octahedral environment defined by four N atoms of the two chelating bpym ligands and two Ianions in a cis-N 4 I 2 coordination geometry. The structure is quite different from the previously reported complexes [MnI(bpym) 2 (H 2 O)]I.xH 2 O obtained from a methanol (x = 2; Ha, 2011a) or a 2-butanone solution (x = 1; Ha, 2011b) of the same reaction product, in which two bpym ligands, an Ianion and a water ligand are coordinated to the Mn II ion, respectively.
The tight N-Mn-N chelating angles and I-I repelling (Table 1) (Table 1), the different trans effects of the I and N atoms cannot be observed reliably. The dihedral angle between the least-squares planes of the two bpym ligands [maximum deviation = 0.098 (3) Å] is 85.04 (6)°. In the crystal, the complex molecules are connected by intermolecular C-H···N and C-H···I hydrogen bonds, forming a three-dimensional network (Fig. 2, Table 2). Molecules are stacked in columns along the a axis.
When viewed down the c axis, successive molecules stack in the opposite directions. In the columns, several inter-and intramolecular π-π interactions between adjacent pyrimidine rings are present, the shortest ring centroid-centroid distance being 3.853 (2) Å.

Experimental
To a solution of 2,2'-bipyrimidine (0.1587 g, 1.003 mmol) in acetone (40 ml) was added MnI 2 (0.1540 g, 0.499 mmol) and refluxed for 3 h. The formed precipitate was separated by filtration, washed with acetone and dried at 50 °C, to give a yellow powder (0.0701 g). Crystals suitable for X-ray analysis were obtained by slow evaporation from a dimethyl sulfoxide  Fig. 1. The structure of the title complex, with displacement ellipsoids drawn at the 40% probability level for non-H atoms. Unlabelled atoms are related to the reference atoms by the (1 -x, y, 1/2 -z) symmetry transformation.