[Bis(3-aminopropyl)amine-κ3 N,N′,N′′]bis(thiocyanato-κN)cobalt(II)

The asymmetric unit of the title compound, [Co(NCS)2(C6H17N3)], consists of one Co2+ cation, two thiocyanate anions and one bis(3-aminopropyl)amine ligand, all in general positions. The cobalt cation is coordinated by five N atoms of two terminal N-bonded thiocyanate anions and one bis(3-aminopropyl)amine ligand, defining a slightly distorted square-pyramidal coordination polyhedron. The molecules are held together in the crystal by weak N—H⋯S interactions.

The asymmetric unit of the title compound, [Co(NCS) 2 -(C 6 H 17 N 3 )], consists of one Co 2+ cation, two thiocyanate anions and one bis(3-aminopropyl)amine ligand, all in general positions. The cobalt cation is coordinated by five N atoms of two terminal N-bonded thiocyanate anions and one bis(3aminopropyl)amine ligand, defining a slightly distorted square-pyramidal coordination polyhedron. The molecules are held together in the crystal by weak N-HÁ Á ÁS interactions.

Comment
Recently, we reported about thermal decomposition reactions as an alternative synthetic strategy for the rational design of condensed frameworks (Wriedt et al. (2009a,b); Wriedt & Näther (2010)). Herein, transition metal(II) thio-and selenocyanato coordination compounds with different neutral N-donor co-ligands are heated, which leads to a stepwise loss of the neutral co-ligands and to the formation of ligand-deficient intermediates. Depending on the precursor, the dimensionality of the resulting intermediates can simply be predefined. If precursors are used, which consist of bidentate co-ligands, (2011)). In further work we tried to synthesize octahedral coordinated precursor compounds based on the tridentate co-ligand bis(3-aminopropyl)amin in combination with a volatile monodentate co-ligand like e.g. water or methanol, which on heating should transform into dimers. Surprisingly a five-coordinated complex was obtained which was characterized by single crystal X-ray diffraction.
In the crystal structure the cobalt(II) cations are coordinated by five nitrogen atoms of two terminal N-bonded thiocyanate anions and one tridenate co-ligand bis(3-aminopropyl)amin in a slightly distorted square-pyramidal coordination geometry ( Fig. 1). The title compound is isostrucutral to its copper(II) and cadmium(II) thiocyanato compounds reported recently (Cannas et al. (1974); Cannas et al. (1977)). These discrete complexes are arranged into columns which elongated in the direction of the crystallographic a axis (Fig. 2). Each two of these columns are pairwise centrosymmetrically arranged into a three-dimensional packing. The molecules are held together by weak N-H···S interactions.

Experimental
The title compound was prepared by the reaction of 96.6 mg Co(NCS) 2 . H 2 O (0.50 mmol), 40.4 µL pyridine (0.50 mmol) and 70.6 µL bis(3-aminopropyl)amine (0.50 mmol) in 1.50 ml water at RT in a closed 3 ml snap cap vial. After one week violet blocks of the title compound were obtained.

Refinement
All H atoms were located in difference map but were positioned with idealized geometry and were refined isotropically with U eq (H) = 1.2 U eq (C) and U eq (H) = 1.2 U eq (N) of the parent atom using a riding model with C-H = 0.99 Å, N-H = 0.93 Å (NH 1 ) and N-H = 0.92 Å (NH 2 ).
supplementary materials sup-2 Figures   Fig. 1. : Crystal structure of the title compound, showing the coordination around the Co 2+ cations with labelling and displacement ellipsoids drawn at the 50% probability level.

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.
Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > 2sigma(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq