Tricyanomethanide ion

Hipps KW, Aplin AT (1985) The tricyanomethanide ion an infrared, Raman, and tunneling spectroscopy study including isotopic substitution. J Phys Chem 89 5459-5464... 

Also possibly involving Mn—C bonds is the compound72 of the tricyanomethanide ion Mn C(CN)3 2 (Me2N)3PO 2. This colourless compound is not isomorphous with the octahedral Ni11 species, but also probably has an octahedral polymeric structure with bridging anions. 

Tricyanomethanide ion. The very small deviations from planarity of this ion observed in certain salts have been attributed to crystal interactions. This ion can form interesting polymeric structures with metal ions. In the argentous compound the group acts as a 3-connected unit in layers based on the simplest 3-connected plane net, and these layers occur as interwoven pairs as described on p. 90. 

Fig. 4 Comparison of Raman, IR, and IETS spectra of the tricyanomethanide (TCM) ion. IETS taken from an Al-AlOx-CsTCM-Pb device. Figure drawn using data from [49]...

Hg2(acridine)2(C104)2 is known by X-ray examination.109 Cyano carbanions such as the tricyanomethanide anion, C(CN)J, the p-tricyanovinylphenyldicyanomethanide and some propionides, e.g. the 1,1,3,3-tetracyanopropionide, form complexes with the Hgj+ ion with N—Hg—Hg—N— bonds.110 Dianions such as 2-dicyanomethylene-l,l,3,3-tetra-... 

The IR spectra and structures of the free tricyanomethanide carbanion and its potassium ion pair have been studied by both spectroscopic experiment and DFT B3LYP force field computations.4 According to the computations, the conversion of the free tricyanomethanide carbanion into an ion pair results in essential changes in the lower-frequency vibration. The experimental geometry agrees with an ion-pair structure with K+ along the C-C=N axis. 

The unique structure adopted by silver tricyanomethanide, Ag[C(CN)3]is illustrated in Chapter 3 (p. 90). It consists of pairs of interwoven hexagonal layers in which Ag is approximately 0-5 A out of the plane of its three N neighbours. Presumably single plane layers would have too open a structure—compare KCu2(CN)3. H2O, in which there are K ions and H2O molecules to occupy the large holes in the sheets. 

An interesting series of structures based on the rutile net illustrates the relationship between interpenetration and self-penetration. The compounds are constructed using octahedral metal ions and the trigonal ligands tcm [tricyanomethanide, C(CN) ] and dca [dicyanamide, N(CN)2 ]. It is important to note that dca is a smaller ligand than tcm. Thus, while the compounds M(tcm)2 have two interpenetrating rutile-related networks,the... 

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