(Acetylacetonato)(dicyanamido)(1,10-phenanthroline)copper(II) dihydrate

In the title compound, [Cu(C5H7O2)(C2N3)(C12H8N2)]·2H2O, the CuII atom is five-coordinated in a square-pyramidal geometry with two acetylacetonate O and two phenanthroline N atoms forming the base. The apical position is occupied by the central N atom of the dicyanamide ligand. The dicyanamide N atoms are each involved in hydrogen bonds to water molecules. There are also hydrogen bonds between both the water molecules and their centrosymmetric pairs, creating a hydrogen-bonded chain along the b-axis direction.

In the title compound, [Cu(C 5 H 7 O 2 )(C 2 N 3 )(C 12 H 8 N 2 )]Á2H 2 O, the Cu II atom is five-coordinated in a square-pyramidal geometry with two acetylacetonate O and two phenanthroline N atoms forming the base. The apical position is occupied by the central N atom of the dicyanamide ligand. The dicyanamide N atoms are each involved in hydrogen bonds to water molecules. There are also hydrogen bonds between both the water molecules and their centrosymmetric pairs, creating a hydrogen-bonded chain along the b-axis direction.

Related literature
Dicyanamide (dca) has been shown to be a versatile ligand and may coordinate to metal ions as a terminal ligand through a nitrile or amide nitrogen. It also acts as a bridging ligand. Until now, as many as eight structurally characterized coordination modes of dicyanamide had been reported in the literature, see: Chattopadhyay et al. (2008); Liu et al. (2005); Miller & Manson (2001); Xu et al. (2003).

Experimental
Crystal data [Cu(C 5 H 7 O 2 )(C 2 N 3 ) (C 12 Table 1 Selected geometric parameters (Å , ).  Data collection: CrysAlis CCD (Oxford Diffraction 2009); cell refinement: CrysAlis RED (Oxford Diffraction, 2009); data reduction: CrysAlis RED; program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: publCIF (Westrip, 2010 Metal dicyanamide (dca) compounds are of great interest due to the variety of observed topologies, this being related to the versatility of dca as a ligand, and its potential application in functional materials. In the present work, we describe the synthesis and crystal structure of a new Cu II complex using the diimine ligand (phen), a bidentate ligand with two oxygen donor atoms (acac) and the anionic co-ligand dicyanamide (dca) (Fig. 1). To date, a number of higher -dimensional coordination networks of different transition metals have been reported with dca as a bridging ligand, but there are few compounds with dca acting as a monodentate ligand through the amide nitrogen. To the best of our knowledge, this complex is one of the few cases where dca is acting as a terminal ligand through the amide nitrogen. The molecule of the title compound is shown in Fig. 1 with selected bond lengths and angles listed in Table 1. In this molecule the coordination is square pyramidal with the two acac O and two phen N atoms forming the base. The apical position is occupied by the N of the dicyanamido ligand with the Cu-N3 distance (Cu1-N3 2.3920 (15) Å) being much greater than those in the basal plane Cu1-O1, 1.906 (1), 1.907 (1) Å and Cu1-N1, 2.010 (1), 2.014 (1) Å. The dicyanamide N atoms, N4, N5 are each involved in hydrogen bonds to water molecules. There are also hydrogen bonds between both the water molecules and their centrosymmetric pairs creating a one dimensional hydrogen bonded polymer in the b direction (see Fig. 2). Geometrical details are listed in Table 2.
Experimental Acetylacetone (0.103 ml, 1 mmol) was added to a 20 ml methanolic solution of CuCl 2 .2H 2 O (170 mg, 1 mmol). After 30 min of stirring, a solution of phen (198 mg, 1 mmol) in 10 ml methanol was added dropwise to this solution. A solution of 1 mmol of sodium dicyanamide (89 mg) dissolved in 5 ml water was then added slowly with stirring. After 10 h of stirring at room temperature, the resulting solution was filtered to remove any undissolved materials. A dark blue crystalline product separated after 2 weeks.

Refinement
All H atoms were positioned geometrically and refined using a riding model with C-H = 0.95-0.98 Å and with U iso (H) = 1.2 times U eq (C) for CH and U iso (H) = 1.5 times U eq (C) for those on terminal C atoms. Anisotropic displacement parameters were employed throughout for the non-hydrogen atoms. Hydrogen atoms on water molecules were located in the difference Hall symbol: -p 1 Mo Kα radiation, λ = 0.71073 Å a = 8.2825 (8) Å Cell parameters from 5220 reflections b = 9.9853 (7) Å θ = 3.5-32.5°c = 12.1109 (7) Å µ = 1.18 mm −1 α = 76.388 (5)°T = 100 K β = 79.236 (7)°Slab, blue γ = 83.554 (7) 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 > σ(F 2 ) is used only for calculating Rfactors(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.
The water molecule hydrogen geometries were restrained to ideal values.

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