Synthesis and Crystal Structure of a New Cu(Ⅱ) Dithiocarbamate Complex CuI(prdtc)(phen)

A new mononuclear Cu（Ⅱ） dithiocarbamate complex CuI（prdtc）（phen） 1 （prdtc = N-pyrrolidinyldithiocarbamate, phen = 1,10-phenanthroline） was synthesized and characterized by elemental analysis, IR spectrum, and single-crystal X-ray diffraction. The crystal belongs to the monoclinic system, space group P21/c with a = 8.7110（9）, b = 14.7143（14）, c = 14.8507（15） A, β = 109.721（6）°, V = 1791.9（3） A3, Z = 4, Dc = 1.916 g/cm3, CI7H16CulN3S2, Mr = 516.89, λ（MoKa） = 0.71073A,μ = 3.178 mm^-1, F（000） = 1012, the final R = 0.0369 and wR = 0.0987. A total of 4082 unique reflections were collected, of which 2916 with I 〉 2σ（I） were observed. The Cu（Ⅱ） atom is five-coordinated in a distorted square-pyramidal geometry by one I atom in the apical position, two S atoms from a prdtc ligand and two N atoms from a phen ligand in the basal plane. There exist face-to-face aromatic π-π stacking interactions between adjacent phen ligands stabilizing the structure and making the complex assemble into a 1D structure along the a axis. It can be concluded that the difference of the dtc flexibility and reaction conditions result in the structural difference between complex 1 and CuI（dmdtc）（phen） （dmdtc = N, N-dimethyldithiocarbamate）.

Synthesis,Crystal Structure and Characterization of a New Mixed-valence Cu(Ⅰ)/Cu(Ⅱ) Complex [Cu(bipy)(Me_2dtc)CuI_2]_n

A new one-dimensional mixed-valence Cu（Ⅰ）/Cu（Ⅱ） complex [Cu（bipy）（Me2dtc）CuI2]n 1 （bipy = 2,2′-bipyridine and Me2dtc = N,N-dimethyldithiocarbamate） has been synthesized under solution condition, and characterized by elemental analysis, IR spectrum, single-crystal X-ray diffraction and magnetic property. The crystal belongs to the tetragonal system, space group P4122 with a = b = 11.6504（16）, c = 13.466（3） A, V = 1827.8（5） A^3, Z = 4, Dc = 2.389 g/cm^3, Mr = 657.27, λ（MoKa） = 0.71073 , μ = 5.931 mm·1, F（000） = 1236, the final R = 0.0483 and wR = 0.1245. A total of 2102 unique reflections were collected, of which 2009 with I 〉 2σ（I） were observed. 1 consists of polymeric [Cu^II2]nn^- anions and [Cu^II（bipy）（Me2dtc）]^＋ cations. It is interesting that the cations of 1 interact through π-π stacking interactions after rotating 90° to form one-dimensional chains parallel to the anion chains. The magnetic study indicates antiferromagnetic behavior for this complex.

Evaluation of particle packing models by comparing with published test results

The existing particle packing density models each with two or more parameters accounting for certain particle interactions （the loosening effect parameter, wall effect parameter, wedging effect parameter, and compaction index, denoted by a, b, c, and K, respectively） may be classified into the 2-parameter model （with a and b incorporated）, the compressible model （with a, b, and 1（incorporated）, and the 3- parameter model （with a, b, and c incorporated）. This paper evaluates these models by comparing their respective packing density predictions with the test results published in the literature. It was found that their accuracy varies with both the size ratio and volumetric fractions of the binary mix. In general, when the size ratio is larger than 0.65, all the packing models are sufficiently accurate. However, when the size ratio is smaller than 0.65, some of them become inaccurate and the errors tend to be larger at around the volumetric fractions giving maximum packing density. Relatively, the 3-parameter model is the most accurate and widely applicable.