Syntheses and Characterization of Diammine–Nickel/Cobalt(II)–Bisdicyanamide M(NH₃)₂[N(CN)₂]₂ with M = Ni and Co

Abstract

Crystals of M­(NH3)2[N­(CN)2]2 with M = Ni and Co were obtained from the reaction of stoichiometric amounts of Na­[N­(CN)2] with NiCl2·6H2O or CoCl2·6H2O in aqueous, ammoniacal solutions. X-ray single-crystal structure analyses show that M­(NH3)2[N­(CN)2]2 with M = Ni and Co crystallize isotypically to each other and adopt the monoclinic space group P21/c (no. 14). The lattice parameters of Ni­(NH3)2[N­(CN)2]2 are a = 5.8498(9) Å, b = 10.6739(12) Å, and c = 6.8089(17) Å, β = 98.037(3)° and Z = 2, while those of Co­(NH3)2[N­(CN)2]2 are a = 5.8303(11) Å, b = 10.746(2) Å, c = 6.7773(13) Å, and β = 96.422(3)°. In addition, the crystal structure of the nickel compound was refined from neutron powder diffraction, augmented by DFT calculations as regards atomic displacement parameters. The IR spectra of the title compounds exhibit modes typical for the dicyanamide anion and ammonia. The UV/vis spectrum of Ni­(NH3)2[N­(CN)2]2 shows that the dicyanamide moiety is a medium-field ligand. Additional superconducting quantum interference device (SQUID) magnetic susceptibility measurements of Ni­(NH3)2[N­(CN)2]2 and Co­(NH3)2[N­(CN)2]2 confirm not only significant high-spin moments of χm T = 1.24 cm3·K·mol–1 (μeff = 3.15 μB) and 2.89 cm3·K·mol–1 (μeff = 4.81 μB), respectively, at 290 K and 0.1 T but also an absence of magnetic ordering.

Ionic Liquids-Driven Cluster-to-Cluster Conversion of Polyhydrido Copper(I) Clusters Cu7H5 to Cu8H6 and Cu12H9

“…44 However, the IR spectrum of Cu 12 H 9 exhibited two (C�N) stretching vibrations at 2250 and 2146 cm −1 , consistent with the bonding mode [η 1 (σ)] of −N�C−N−C�N from IL-N(CN) 2 to the copper(I) ion. 45 To further confirm the formulation, the deuteride clusters Cu S1 and S2). As shown in Figure 2, the dicationic skeleton of Cu 7 H 5 contains a distorted monocapped trigonal antiprism or an octahedron Cu 7 core, supported by six edge-bridged dppy ligands.…”

“…As shown in Figure S3, the IR spectrum of Cu 8 H 6 displayed three strong peaks at 1344, 1132, 1179, and 1050 cm –1 , respectively, similar to that observed in IL-NTf 2 , which are ascribed to the antisymmetric/symmetric stretching vibration of sulfonyl (−SO 2 −), the bending vibration of trifluoromethyl (−CF 3 ), and −SNS–, respectively . However, the IR spectrum of Cu 12 H 9 exhibited two (CN) stretching vibrations at 2250 and 2146 cm –1 , consistent with the bonding mode [η 1 (σ)] of −NC–N–CN from IL-N(CN) 2 to the copper(I) ion . To further confirm the formulation, the deuteride clusters Cu 7 D 5 , Cu 8 D 6 , and Cu 12 D 9 were also prepared using NaBD 4 instead of NaBH 4 .…”

3D-Cobalt-Dicyanamide-Derived 2D-Layered-Co(OH)2-Based Catalyst for Light-Driven Hydrogen Evolution

“…For Co-dca, all three bands shift to higher wavenumbers (2206, 2269, and 2315 cm –1 , respectively) due to the coordination of dca to Co sites (Figure b). − Moreover, the absorption bands of the ν s (N–C) and ν as (N–C) stretching modes are observed at 964 and 1314 cm –1 , respectively (Figure S1). , The assignment of the other vibrations can be found in Table S1.…”

“… 43 − 45 Moreover, the absorption bands of the ν s (N–C) and ν as (N–C) stretching modes are observed at 964 and 1314 cm –1 , respectively ( Figure S1 ). 37 , 46 The assignment of the other vibrations can be found in Table S1 .…”

Synthesis and Characterization of Iron Bispyridine Bisdicyanamide, Fe[C5H5N]2[N(CN)2]2

“…By introducing neutrally charged, non-bridging ligands L (e.g., DMF, EtOH, pyridine [ 33 , 34 ], pyridazine [ 35 , 36 ], and ammonia [ 37 , 38 ]) to these 3D metal dicyanamides, both structure and properties change to a structure type between the α- and the β-structures. In the latter structure type, only the terminal nitrogen atoms of the dca units are μ -1,5 bridging the metals, as said before, so the additional L ligands complete the octahedral metal coordination.…”