The crystal and molecular structure of bis-(2-thioimidazolidine)-nickel(II) thiocyanate

Abstract

The crystal structure of bis-(2-thioimidazolidine)nickel thiocyanate, Ni[SC(NHCHz)2]2(NCS)2, has been determined and refined by three-dimensional Fourier methods (final R = 11.6 Vo). There is one formula unit in the triclinic (PI) unit cell: a=5.592(21), b=8-664(18), c= 8-686(22) /~, e=113°39"(7'), B= 95°8'(7'), 9= 108°43"(6'). Each nickel atom is octahedrally surrounded by two sulphur atoms (Ni-S 2.51/~) from two thioimidazolidine molecules, and by two sulphur atoms (Ni-S 2-54/~) and two nitrogen atoms (Ni-N 1.99/~) from four different NCS groups. These nitrogen atoms are trans with respect to the plane of the sulphur atoms. The octahedra are linked in zigzag chains by the NCS groups, which form bridges between adjacent nickel atoms. The thioimidazolidine molecule is not strictly planar, the two CH2 groups being shifted by ~ 0. I/~ on opposite sides of the plane of the thiourea part of the molecule. The infrared C-S and C-N stretching frequencies of bridged NCS groups in some thioimidazolidine-metal complexes are compared. Structure analysis and refinementThe structure was solved directly, assuming all the structure factors to be positive in the first Fourier calculation. This implied the assumption of the space group Pi with the choice of origin at the Ni atom, which is heavy enough to dominate the majority of the signs. In this way the S atoms were located first and all the other atoms were located in successive calculations.The refinement was carried out in the P i space group by means of Booth's differential syntheses with anisotropic thermal parameters. These parameters were derived from the second derivatives of the electron-density from differential synthesis, following the method of . At the end of this refinement, the ratios r(x)=~r(x)/e(x) between the e.s.d.'s and the shifts of the coordinates were as shown in Table 1 and the agreement indices (R, for observed reflexions only; R' assuming Fo = ½Fmln when Fc > Frnin for unobserved reflexions; multiplicities not considered) were: R---11.6~, R'= 13.0~. NARDELLI, GASPARRI, MUSATTI AND MANFREDOTTI 911

Metal Derivatives of 1,3‐Imidazolidine‐2‐thione with Divalent d10 Metal Ions (Zn–Hg) : Synthesis and Structures

“…The 1,3-imidazolidine-2-thione (imdtH 2 , I), with functional moiety ϪN(H)-C(ϭS)-N(H)Ϫ, is one of the simplest heterocyclic thioamides. As a neutral ligand, it has shown several bonding modes, namely, (i) η 1 -S (II) [17], (ii) μ 2 -S (III) [12], (iii) μ 3 -S (IV) [18], and as an anionic ligand, only μ-N, S mode (V) is known [10,15] (Chart 1).…”

Mössbauer and Infrared Spectra of Tetrahedral Complexes of Iron(II) Halides with Thioamides and Related Ligands

“…have been characterized by means of their electronic spectra (1-6) and more recently by Mossbauer spectroscopy (7,8). This latter technique has been invaluable in detecting Jahn Teller distortion A ( Complexes of the type FeX2L2 are also known where X = halogen and L = pyridine and substituted pyridines (1), triphenylphosphine (9, lo), triphenyl arsine (2), quinoline and 3-methylisoquinoline (1 I), benzothiazole (3), thioacetamide (12)(13)(14), and thiourea (15). With this stoichiometry (FeX2L2) it is, however, not necessary that the environment about the iron be tetrahedral.…”

The crystal and molecular structure of bis(thiourea)iron (11) thiocyanate

“…The stabilization of the polymeric chains is due to the close approach of the sulfurs of the thiocyanate group to a nitrogen of the thiourea of the next chain, so generating a packing structure as shown in Figure 3 and Table 5 where some intermolecutar Table 5. The most significant van der Waals interactions (A) S(I)-S(1)(1-x, l-y, l-z) 3.47(1) S(1)-N(2)(~, l-y, l-z) 3.53(2) S( 1 )-N(2)(~, 1 -~, ~-) 3.63(2) S(1)-N(3) (1 + x,y, z) 3.48(2) S(1)-N(3)(1 + x, y, 1 + z) 3.53 (2) 2-thioimidazoline ligand is the polymeric octahedral structure stable, even if the nickel atoms are linked by thiocyanate bridges (18). On the contrary, bulky ligands such as diethylthiourea (detu) destabilize the polymeric chain and the monomeric tetrahedral complex Ni(detu)2(NCS)2 is formed (19).…”