“…The present study is the first on a cyano complex of silver(III), and a comparison of the Ag−CN distance with those reported for [Ag(CN) 2 ] - salts is complicated by the secondary interactions which they often enter. However, for structures , in which the anion is essentially isolated and σ(Ag−C) is less than 0.01 Å, the average Ag−C bond length (2.053(7) Å) appears to be significantly longer than that of the present structure. 9 Perspective drawing of the [ trans -Ag(CF 3 ) 2 (CN) 2 ] - anion in [PPh 4 ][ trans -Ag(CF 3 ) 2 (CN) 2 ] with 20% probability thermal ellipsoids.…”
Trifluoromethylation of [Ag(CN)(2)](-) with (CF(3))(2)Cd.diglyme yields [Ag(CF(3))(CN)](-). The anion is readily oxidized by bromine to the argentates(III), [Ag(CF(3))(n)(CN)(4-n)](-), n = 1-4. The stability of these species decreases with an increasing number of CN groups. Halogenation of these complexes with acetyl chloride or with bromine affords the moderately stable (n = 3) or unstable (n = 2) haloargentates of the type [Ag(CF(3))(n)X(4-n)](-), X = Cl or Br. Their dehalogenation with AgNO(3) in a donor solvent D gives the adducts [Ag(CF(3))(3)D] and [Ag(CF(3))(2)D(2)](+), respectively. Decomposition of most argentates(III) proceeds by reductive elimination of CF(3)X (X = Cl, Br, or CN), but ligand exchange with participation of the CF(3) groups is also observed. The latter is used to prepare Ag(CF(3))(3) derivatives from the readily accessible [trans-Ag(CF(3))(2)(CN)(2)](-) anion. The syntheses of methyl(trifluoromethyl)argentates(III) and of (cyclohexylethynyl)(trifluoromethyl)argentates(III) are accomplished by reaction of the cyanoargentates (n = 2, 3) with CH(3)MgCl or LiC&tbd1;CC(6)H(11), respectively. Often multinuclear ((109)Ag, (19)F, (13)C, (1)H) NMR data of transient and stable Ag(III) species establish unambiguously not only their constitution but also the square-planar coordination of the metal. Couplings to the spin-(1)/(2) silver nuclei are interpreted on the basis of 5s(Ag) orbital participation in competition with 4d orbital contributions to Ag-CF(3) bonding. Crystals of [PPh(4)][Ag(CF(3))(2)(CN)(2)] belong to the monoclinic space group C2/c, with a = 18.174(2) Å, b = 7.8881(8) Å, c = 18.881(2) Å, beta = 93.036(8) degrees, and Z = 4, whereas [PPh(4)][Ag(CF(3))(3)(CH(3))] crystallizes in the orthorhombic space group Pca2(1), with a = 24.941(3) Å, b = 7.2629(6) Å, c = 14.9985(14) Å, and Z = 4. The coordination environments of these two argentates are approximately square planar. The Ag-CF(3) bonds in the dicyano complex (2.105(4) Å) are distinctly longer than the Ag-CN linkages (2.013(3) Å). In the [Ag(CF(3))(3)(CH(3))](-) anion, the Ag-CH(3) distance (2.097(5) Å) is slightly shorter than the average Ag-CF(3) bond lengths (2.119(10) Å).
“…The present study is the first on a cyano complex of silver(III), and a comparison of the Ag−CN distance with those reported for [Ag(CN) 2 ] - salts is complicated by the secondary interactions which they often enter. However, for structures , in which the anion is essentially isolated and σ(Ag−C) is less than 0.01 Å, the average Ag−C bond length (2.053(7) Å) appears to be significantly longer than that of the present structure. 9 Perspective drawing of the [ trans -Ag(CF 3 ) 2 (CN) 2 ] - anion in [PPh 4 ][ trans -Ag(CF 3 ) 2 (CN) 2 ] with 20% probability thermal ellipsoids.…”
Trifluoromethylation of [Ag(CN)(2)](-) with (CF(3))(2)Cd.diglyme yields [Ag(CF(3))(CN)](-). The anion is readily oxidized by bromine to the argentates(III), [Ag(CF(3))(n)(CN)(4-n)](-), n = 1-4. The stability of these species decreases with an increasing number of CN groups. Halogenation of these complexes with acetyl chloride or with bromine affords the moderately stable (n = 3) or unstable (n = 2) haloargentates of the type [Ag(CF(3))(n)X(4-n)](-), X = Cl or Br. Their dehalogenation with AgNO(3) in a donor solvent D gives the adducts [Ag(CF(3))(3)D] and [Ag(CF(3))(2)D(2)](+), respectively. Decomposition of most argentates(III) proceeds by reductive elimination of CF(3)X (X = Cl, Br, or CN), but ligand exchange with participation of the CF(3) groups is also observed. The latter is used to prepare Ag(CF(3))(3) derivatives from the readily accessible [trans-Ag(CF(3))(2)(CN)(2)](-) anion. The syntheses of methyl(trifluoromethyl)argentates(III) and of (cyclohexylethynyl)(trifluoromethyl)argentates(III) are accomplished by reaction of the cyanoargentates (n = 2, 3) with CH(3)MgCl or LiC&tbd1;CC(6)H(11), respectively. Often multinuclear ((109)Ag, (19)F, (13)C, (1)H) NMR data of transient and stable Ag(III) species establish unambiguously not only their constitution but also the square-planar coordination of the metal. Couplings to the spin-(1)/(2) silver nuclei are interpreted on the basis of 5s(Ag) orbital participation in competition with 4d orbital contributions to Ag-CF(3) bonding. Crystals of [PPh(4)][Ag(CF(3))(2)(CN)(2)] belong to the monoclinic space group C2/c, with a = 18.174(2) Å, b = 7.8881(8) Å, c = 18.881(2) Å, beta = 93.036(8) degrees, and Z = 4, whereas [PPh(4)][Ag(CF(3))(3)(CH(3))] crystallizes in the orthorhombic space group Pca2(1), with a = 24.941(3) Å, b = 7.2629(6) Å, c = 14.9985(14) Å, and Z = 4. The coordination environments of these two argentates are approximately square planar. The Ag-CF(3) bonds in the dicyano complex (2.105(4) Å) are distinctly longer than the Ag-CN linkages (2.013(3) Å). In the [Ag(CF(3))(3)(CH(3))](-) anion, the Ag-CH(3) distance (2.097(5) Å) is slightly shorter than the average Ag-CF(3) bond lengths (2.119(10) Å).
“…The layers of discrete [Ag(CN) 2 ] - anions and the respective Cd complex cations are alternately stacked along the c axis in the structures of 1b , 2 , and 3 ; 1a also has the analogous layered array of the propellers stacked along both b and c axes. The layered crystal structure involving dicyanoargentate(I) appears to be rather common even for a single complex salt such as Na[Ag(CN) 2 ] or K 2 Na[Ag(CN) 2 ] 3 …”
The crystal structures of four
[dicyanoargentato(I)]cadmium(II) complexes with the
mixed ligation of imidazole
(imH: C3H4N2) or
N-methyl- or 2-methylimidazole (N-Meim or
2-MeimH: C3H6N2) on the
cadmium(II), [Cd(imH)4{Ag(CN)2}2]
(1a),
[Cd(imH)5{Ag(CN)2}][Ag(CN)2]
(1b),
[Cd(N-Meim)4{Ag(CN)2}][Ag(CN)2]
(2), and
[Cd(2-MeimH)4{Ag(CN)2}][Ag(CN)2]·H2O
(3), have been determined by single-crystal X-ray
diffraction methods.
Complex 1a crystallizes in the orthorhombic
Pbmn space group with a = 22.206(2) Å,
b = 10.306(1) Å, c =
10.318(1) Å, Z = 4. 1b: monoclinic
P21/n, a = 9.028(4)
Å, b = 13.988(6) Å, c = 22.079(4)
Å, β = 101.02(2)°,
Z = 4. 2: monoclinic
C2/m, a = 11.1292(8) Å,
b = 11.435(3) Å, c = 11.266(1) Å,
β = 94.252(8)°, Z = 2.
3:
orthorhombic Pnnm, a = 11.212(2) Å,
b = 11.156(5) Å, c = 23.646(5) Å,
Z = 4. Complex 1a has the shape
of
a four-blade propeller consisting of
[Cd(imH)4]2+ with the shaft being the
monodentate [−NCAgCN]- anions.
1b comprises the discrete
[Ag(CN)2]- and the umbrella-shaped
[Cd(imH)5NCAgCN]+ in which the
monodentate
[Ag(CN)2]- behaves as the shank;
hydrogen-bond networks among the umbrellas build up a
three-dimensional
lattice. In 2 and 3 the four-blade
propellers of
[Cd(N-Meim)4]2+ and
[Cd(2-MeimH)4]2+ are successively
linked
at every Cd by the ambidentate −NCAgCN− rods to form an infinite
chain, respectively; the discrete
[Ag(CN)2]-
anions and the H2O in 3 are accommodated in the
interchain space. The varieties in coordination behavior
of
[Ag(CN)2]- can be interpreted in terms
of the hydrogen-bond formation between a pyrrole H of the
imidazole
ligand and an unbridged N-end of
[Ag(CN)2]-.
“…The shortest Ag−Ag distance of 3.11 Å observed in Tl[Ag(CN) 2 ] is shorter than any reported Ag−Ag distance among the silver dicyanide salts whose crystal structures have been determined. For example, the shortest silver−silver distance has been reported as 3.71 and 3.52 Å in Na[Ag(CN) 2 ] and K 2 Na[Ag(CN) 2 ] 3 , respectively. Crystal structures have also been determined for K[Ag(CN) 2 ], M[Ag(CN) 2 ] 2 ·2H 2 O (M = Ca, Sr), and Rb{Cd[Ag(CN) 2 ] 3 } …”
The structure of thallium dicyanoargentate(I) has been determined crystallographically. The crystal structure shows an Ag-Ag distance of 3.11 Å. This is the shortest Ag-Ag distance reported for any silver dicyanide salt whose crystal structure has been determined. Raman spectra of the compound show four nu(C)(-)(N) peaks that are well-resolved in the 10-80 K temperature range. This result agrees well with group theory analysis. Extended Hückel calculations using relativistic wave functions have been carried out for two models which describe the interactions between the Ag(CN)(2)(-) ions within the crystal structure of Tl[Ag(CN)(2)]. The results of these calculations indicate the formation of potential wells at short Ag-Ag distances. The data in this study suggest the significance of ligand-unsupported silver-silver interactions (argentophilicity) in Tl[Ag(CN)(2)]. Tl-Ag interactions are determined to be insignificant in the compound. Tl[Ag(CN)(2)] crystallizes in the monoclinic space group P2(1)/c (No. 14), with a = 7.798(1) Å, b = 14.685(3) Å, c = 8.566(2) Å, beta = 91.66(2) degrees, Z = 8, R = 0.0643, and R(w) = 0.0899.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
