N-(4-Methylpiperazin-4-ium-1-yl)dithiocarbamate sesquihydrate

In the crystal structure of the title compound, C6H13N3S2·1.5H2O, weak N—H⋯S interactions between the zwitterionic molecules are observed, leading to an extensively folded layered arrangement parallel to (100). There are three crystallographically independent water molecules in the asymmetric unit, which are disordered and only half occupied.

In the crystal structure of the title compound, C 6 H 13 N 3 S 2 Á-1.5H 2 O, weak N-HÁ Á ÁS interactions between the zwitterionic molecules are observed, leading to an extensively folded layered arrangement parallel to (100). There are three crystallographically independent water molecules in the asymmetric unit, which are disordered and only half occupied.
There are no significant differences in NCS 2 group geometry compared to other compounds of this type. The notable feature of the title compound is the presence of the intermolecular interactions (Table 1). Eeach molecule of the title compound serves to its close neighbors as a hydrogen bond donor (via N-H groups) and acceptor (via S atoms, see Additional water molecules are present in vicinity of the twofold axis and are disordered (see experimental refinement section for details).

Experimental
A stoichiometric amount (0.325 g, 0.26 cm 3 ) of carbon disulfide, CS 2 , was added dropwise to a methanol/H 2 O (10:1, v/v) solution containing 0.5 g (0.52 cm 3 ) 1-amino-4-methylpiperazine and 0.24 g potassium hydroxide. The mixture had been stirred for ca 25 min until a white precipitate appeared. The clear filtrate was then left at temperature of 5°C for crystallization. After 5 days, well shaped, colorless needle-like crystals suitable for X-ray analysis were collected. Then, the mother liquor was concentrated and after few days more product was isolated. The overall yield was ca 50%. The presence of O-H groups was confirmed by FTIR analysis of single crystals taken from the mother liquor using Mattson Genesis II Gold spectrometer equipped with Momentum Microscope as detector (a broad maximum of absorption at 3434 cm -1 together with a sharp one at 3239 cm -1 ). However, the product, when taken from the mother liquor and dried using the filter paper, changes -becomes at first opaque and finally takes the form of a powder (most probably because of The melting point for the title compound (for 10 °/min heating rate) was determined to be 129°C.

Refinement
All C-H atoms were placed in calculated positions (methyl H atoms allowed to rotate but not to tip) and refined as riding on their carrier atoms with respective bond lengths and U iso (H) values: C-H = 0.96 Å (CH 3 ) and U iso (H) = 1.5 U eq (C), C-H = 0.97 Å (CH 2 ) and U iso (H) = 1.2 U eq (C). Refirement of N-H was carried out withouth restrains.
After refinement of the zwitterionic molecule three electron density peaks are observed that were assigned to three disordered and half-occupied oxygen atoms with distances O1-O2 and O2-O3 2.734 (5) and 2.845 (5) Å, respectively.
The symmetry equivalent atoms constitute the second disorder part. The connectivity table was adjusted by using PART -1 SHELX instruction to avoid creating bonds to symmetry equivalent oxygen atoms (generated by the twofold axis).
Hydrogen atoms bound to O1 and O2 are directed towards acceptor atoms and could have been found and refined as restrained. Positions of H3C and H3D hydrogen atoms were restrained to target 0.85 (2)     Special details Experimental. Absorption correction: CrysAlis PRO (Oxford Diffraction, 2008). Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm. Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'s 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 > 2σ(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.

Crystal data
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )