Syntheses and Characterization of Two Dicyanamide Compounds Containing Monovalent Cations: Hg2[N(CN)2]2 and Tl[N(CN)2]

Crystals of Hg2[N(CN)2]2 were grown by a slow diffusion-reaction between aqueous Hg2(NO3)2·2H2O and Na[N(CN)2</sub&g...

Bibliographic Details
Main Authors:	Markus Mann, Olaf Reckeweg, Nils Nöthling, Richard Goddard, Richard Dronskowski
Format:	Article
Language:	English
Published:	MDPI AG 2018-12-01
Series:	Inorganics
Subjects:	dicyanamide mercury thallium crystal structure volume chemistry IR spectrum metathesis
Online Access:	https://www.mdpi.com/2304-6740/6/4/135

Description
Summary:	Crystals of Hg<sub>2</sub>[N(CN)<sub>2</sub>]<sub>2</sub> were grown by a slow diffusion-reaction between aqueous Hg<sub>2</sub>(NO<sub>3</sub>)<sub>2</sub>·2H<sub>2</sub>O and Na[N(CN)<sub>2</sub>]. Hg<sub>2</sub>[N(CN)<sub>2</sub>]<sub>2</sub> adopts the triclinic space group <i>P</i><inline-formula> <math display="inline"> <semantics> <mover accent="true"> <mn>1</mn> <mo>¯</mo> </mover> </semantics> </math> </inline-formula> (no. 2) with <i>a</i> = 3.7089(5), <i>b</i> = 6.4098(6), <i>c</i> = 8.150(6) Å, <i>α</i> = 81.575(6)°, <i>β</i> = 80.379(7)°, <i>γ</i> = 80.195(7)°, and <i>Z</i> = 1. Crystals of Tl[N(CN)<sub>2</sub>] were obtained from the reaction of TlBr with Ag[N(CN)<sub>2</sub>] in water. Single-crystal structure analyses evidence that Tl[N(CN)<sub>2</sub>] is isotypic to <i>α</i>-K[N(CN)<sub>2</sub>] and adopts the orthorhombic space group <i>Pbcm</i> (no. 57) with <i>a</i> = 8.5770(17), <i>b</i> = 6.4756(13), <i>c</i> = 7.2306(14) Å, and <i>Z</i> = 4. Regarding volume chemistry, the dicyanamide anion occupies ca. 44 cm<sup>3</sup>·mol<sup>−1</sup>, and so it corresponds to a large pseudohalide. The IR spectra of both compounds exhibit vibrational modes that are characteristic of the dicyanamide anion.
ISSN:	2304-6740

Syntheses and Characterization of Two Dicyanamide Compounds Containing Monovalent Cations: Hg<sub>2</sub>[N(CN)<sub>2</sub>]<sub>2</sub> and Tl[N(CN)<sub>2</sub>]