Abstract
The KSCN complex of 5, 5'-carbonylbis [1, 3-dimethyl-3, 4, 5, 6-tetrahydro-1, 3, 5-triazin-2 (1H) -one] (CDTTO) (KSCN : CDTTO = 1 : 1) was prepared. The molecular structure of this complex was determined by means of X-ray analysis and compared with the molecular structure of the CuC12complex of CDTTO. A white transparent crystal with dimensions of ca. 0.2*0.2*0.3mm3 was mounted on a Rigaku AFC-6S automated diffractometer.
Crystal Data, C11H20N6O3·KSCN· H2O, F.W.= 399.54, monoclinic, space group P21/c, a =11.745 (2), b = 23. 357 (7), c= 7. 010Å (2), β= 98.85 (2) °, V=1900. 3Å3, Z = 4, Dc =1. 40g/cm3, μ (Mo Kα) =4.1cm-1
The structure was solved by the direct method and refined anisotropically for Non-H atoms and isotropically for H atoms by a block-diagonal least-squares method. The final discrepancy factors were R = 0.066 and Rω= 0.068. The crytal has one mole of water of crystallization per mole of the complex.
The four atoms of C (1) O (1), N (1), and N (4) lie nearly on the same plane. The least-squares planes formed by the seven atoms of N (1) - (3), C (2) - (4), and O (2) and by the other seven atoms of N (4) - (6), C (5) -C (7), and O (3) intercept the former plane (the ureido moiety) at 97. 4 and 83.5°, respectively. The bond lengths for the carbonyl groups of C (1) -O (1), C (4) -O (2), and C (7) -O (3) are 1.212, 1.240, and 1. 230Å, respectively. While C (1) -O (1) has a strong double bond character, C (4) -O (2), and C (7) -O (3) are intermediate between single and double bonds. These carbonyl bonds are shorter than that of C (4) -O (2) in the CDTTO-CuC12 complex. This difference is due to the absence and presence of stabilization of the anionic structure of oxygen atoms by the absence (CDTTO-KSCN) and presence (CDTTO-CuC12) of the coordination to cation.
The distance between K+and NCS-is 2.884Å and suggests a strong interaction. The distance between K+and oxygen or nitrogen atom in CDTTO molecule suggests no coordination of K+to these atoms. These results suggest that KSCN may be stabilized together with the water of crystallization in the cavities formed by the CDTTO molecules.
