Preparation, Spectroscopic Characterization and Crystal Structures of Mercury(II)‐bis(tetracyanoborate) Hg[B(CN)₄]₂ and Dimercury(I)‐bis(tetracyanoborate) Hg₂[B(CN)₄]₂.

Abstract

-Compounds (III) and (V) are characterized by IR, Raman, and NMR spectroscopy, and by single crystal XRD. (III) crystallizes in the trigonal space group P3m1 with Z = 1 and (V) in the orthorhombic space group Pbcm with Z = 4. In the crystal structure of (III) the Hg 2+ ion is octahedrally coordinated by six N atoms of six [B(CN) 4 ] − anions. The structure of compound (V) contains Hg 2 2+ ions bridged via N atoms.

Nickel(II) Cyanoborates and Cyanoborate-Ligated Nickel(II) Complexes

“…Interestingly, some ligand environments of transition-metal complexes may even allow the formation of monodentate coordinated complexes for cyanoborate anions with more than one CN group, e.g., in the copper complexes [Cu(PPh 2 Me) 2 (NC-BH 2 CN)] and [P 3 Cu(NC-BH 2 CN)] (P 3 = 1,1,1- tris- ((diphenylphosphino)methyl)-ethane) or in the zirconocene complexes [Cp 2 Zr(CH 3 )(NC-BR 3 )] and [Cp 2 Zr(NC-BR 3 ) 2 ] (R = CN, CF 3 ) . More often, such cyanoborate anions and transition-metal ions and fragments tend to form polynuclear compounds, as observed for the coordination polymers false[ normalM false{ μ 2 − ∞ 3 [B(CN) 4 ]} 2 (H 2 O) 2 ] (M = Fe, Co), false[ normalM { μ 3 − ∞ 3 [BF(CN) 3 ]}] (M = Cu, Ag), false[ normalM { μ 4 − ∞ 3 [B(CN) 4 ]}] (M = Cu, Ag), false[ normalM false{ μ 3 − ∞ 3 [B(CN) 4 ]} 2 ] (M = Cu, Zn, Hg, Hg 2 ), [ Cu I false{ μ 3 − ∞ 2 [PhB(CN) 3 ]}(MeCN)], false[ normalK ( 18 − crown − 6 ) ∞ 2 Cu{μ ...…”

“…35−37 Early on, it was noted that cyanoborate anions have the ability to coordinate via the N atom(s) of the cyano group(s) to metal centers, e.g., coordination networks are typically obtained with metal cations such as alkali metal cations, 38−41 Ag + , 41 and Hg 2+ . 42 However, comparably little is known about the coordination chemistry of cyanoborate anions of the general formula [R 4−m B(CN) m ] − (m = 1−3) with respect to different transition-metal precursors. 1 This is not surprising, considering the low electron density of the cyanoborate anions and the efficient delocalization of the negative charge caused by the electronegative cyano substituents, which lowers the overall reactivity (vide supra) and coordination ability of cyanoborate anions, in general.…”

“…Early on, it was noted that cyanoborate anions have the ability to coordinate via the N atom(s) of the cyano group(s) to metal centers, e.g., coordination networks are typically obtained with metal cations such as alkali metal cations, − Ag + , and Hg 2+ . However, comparably little is known about the coordination chemistry of cyanoborate anions of the general formula [R 4– m B­(CN) m ] − ( m = 1–3) with respect to different transition-metal precursors .…”

“…Interestingly, some ligand environments of transition-metal complexes may even allow the formation of monodentate coordinated complexes for cyanoborate anions with more than one CN group, e.g., in the copper complexes [Cu­(PPh 2 Me) 2 (NC-BH 2 CN)] and [P 3 Cu­(NC-BH 2 CN)] (P 3 = 1,1,1- tris- ((diphenylphosphino)­methyl)-ethane) or in the zirconocene complexes [Cp 2 Zr­(CH 3 )­(NC-BR 3 )] and [Cp 2 Zr­(NC-BR 3 ) 2 ] (R = CN, CF 3 ) . More often, such cyanoborate anions and transition-metal ions and fragments tend to form polynuclear compounds, as observed for the coordination polymers [B­(CN) 4 ]} 2 (H 2 O) 2 ] (M = Fe, Co), [BF­(CN) 3 ]}] (M = Cu, Ag), [B­(CN) 4 ]}] (M = Cu, Ag), [B­(CN) 4 ]} 2 ] (M = Cu, Zn, Hg, Hg 2 ), [PhB­(CN) 3 ]}­(MeCN)], Cu­{μ 3 – [PhB­(CN) 3 ] 2 ], [PhB­(CN) 3 ]}­(PCy 3 ) 2 ], and the hexa­nuclear complex salt {THF ⊂ [PhB­(CN) 3 ] 6 [Cp*Rh] 6 }­(CF 3 SO 3 ) 6 . In summary, the aforementioned examples demonstrate the tunability of the coordination scheme dependent on the cyanoborate anion, the metal ion, and additional coligands.…”