Crystal structure of [{[Ni(C₁₀H₂₄N₄)][Ni(CN)₄]}·2H₂O]_n, a one-dimensional coordination polymer formed from the [Ni(cyclam)]²⁺cation and the [Ni(CN)₄]^2–anion

Abstract

The asymmetric unit of the title compound, catena-poly[[[(1,4,8,11-tetraazacyclotetradecane-κ4 N 1,N 4,N 8,N 11)nickel(II)]-μ-cyanido-κ2 N:C-[bis(cyanido-κC)nickel(II)]-μ-cyanido-κ2 C:N] dihydrate], {[Ni2(CN)4(C10H24N4)]·2H2O] n or [{[Ni(C10H24N4)][Ni(CN)4]}·2H2O] n , consists of a pair of crystallographically non-equivalent macrocyclic cations and anions. The nickel(II) ions (all with site symmetry \overline{1}) are coordinated by the four secondary N atoms of the macrocyclic ligands, which adopt the most energetically stable trans-III conformation, and the mutually trans N atoms of the tetracyanonickelate anion in a slightly tetragonally distorted NiN6 octahedral coordination geometry. The [Ni(CN)4)]2– anion exhibits a bridging function, resulting in the formation of parallel polymeric chains running along the [1\overline{1}0] direction. The water molecules of crystallization play a pivotal role in the three-dimensional supramolecular organization of the crystal. Acting as acceptors, they form N—H...Ow (w = water) hydrogen bonds with the secondary amino groups of the macrocycles, forming layers oriented parallel to the (001) plane. At the same time, as donors, they interact with the non-coordinated cyano groups of the anion via Ow—H...Nc (c = cyanide) hydrogen bonds, giving two-dimensional layers oriented parallel to the (100) plane and thus generating a three-dimensional network.

Crystal Engineering and Photomagnetic Studies of CN-Bridged Coordination Polymers Based on Octacyanidometallates(IV) and [Ni(cyclam)]2+

“…If the crystals of 4 are filtered off and the filtrate is left at room temperature, an additional product of the formula [Ni­(cyclam)]­[Ni­(CN) 4 ]·2H 2 O ( 5 ) is obtained after about 2 weeks in the form of light pink crystals. The same compound was obtained by a different method and structurally characterized earlier . We also obtained 5 in an alternative synthesis by mixing equimolar amounts of [Ni­(cyclam)] 2+ and [Ni­(CN) 4 ] 2– dissolved in 1.4 mol·dm –3 potassium nitrate water solution at 65 °C.…”

Phase Transition and Switchable Dielectric Properties of a Three-Dimensional Hydrogen-Bonding Framework Based on Cobalt (Ⅲ), o-Bromoaniline, and 18-Crown-6

“…Typically, electrical, magnetic, or optical responses tend to change abruptly close to the phase transition temperature. Organic-inorganic hybrids have emerged as favorable candidates for integrating phase transition properties with diverse switching response characteristics [24][25][26][27][28]. For responsive dielectrics, the dipolar orientation (e.g., order-disorder or melting/frozen-like transition) is the primary contributor to the dielectric constant.…”