Additions and corrections
Silver cages with encapsulated acetylenediide as building blocks for hydrothermal synthesis of supramolecular complexes with n-cyanopyridine and pyridine-n-carboxamide (n = 3, 4)
Xiao-Li Zhao and Thomas C. W. Mak
Dalton Trans., 2004, 3212–3217 (DOI: 10.1039/b406711h). Amendment published 6th April 2005.
The reported C–C triple bond length of 1.03(2) Å for compound 3 is abnormally short, as noted by Prof. R. Hoffmann in his letter to us. Data re-collected at 123 K yielded a b-axis three times as long, and subsequent refinement showed that the three independent C–C triple bond distances (1.235(9), 1.183(9), 1.198(9) Å) are all normal. The overall structure remains unchanged.
New data for compound 3. C114H70Ag24F54N24O48, M = 6158.82, monoclinic, a = 18.382(1), b = 55.376(3), c = 15.873(1) Å, β = 94.286(1)°, V = 16112.1(17) Å3, T =123 K, space group Cc (no. 9), Z = 4, μ(Mo-Kα) = 2.989 mm−1, 57985 reflections measured, 26023 unique (Rint = 0.0265) which were used in all calculations. The final R1 and wR2 were 0.0327 and 0.0732 (I > 2σI).
Availability of the new data necessitates an updated structural description of compound 3, as given below, and Figs. 6–8 in the paper have to be replaced by new ones. X-Ray crystal structure analysis showed that compound 3 is a three-dimensional framework composed of C2@Ag8 cages interlinked by pyridine-3-carboxamide ligands. There are three similar independent silver cages in the asymmetric unit, each taking the shape of a distorted bicapped trigonal prism, as shown in Fig. 6.
Fig. 6 Three similar distorted bicapped trigonal prismatic C2@Ag8 cages in 3.
Twelve independent pyridine-3-carboxamide ligands, labeled I–XII [Fig. 7(a)], exist in the asymmetric unit of 3. According to their linkage mode in the construction of the three-dimensional structure, the amide ligands can be classified into four types: (I and II), (III and IV), (V, VI, VII, VIII, IX and X) and (XI and XII). Ligands I–IV and XI–XII link the C2@Ag8 cages to form a (4,4) layer [Fig. 7(b)], and such layers are further pillared into a three-dimensional framework (Fig. 8) via the remaining amide ligands.
Fig. 7 (a) Twelve independent pyridine-3-carboxamide ligands linking the single silver(I) cages in 3. Trifluoroacetate ligands are omitted for clarity. (b) A (4,4) network constructed from pyridine-3-carboxamide ligands of type I–II, III–IV and XI–XII.
Fig. 8 Three-dimensional architecture of 3 generated from pyridine-3-carboxamide ligands V, VI, VII, VIII, IX and X acting as pillars that support adjacent (4,4) networks.
The Royal Society of Chemistry apologises for this error and any consequent inconvenience to authors and readers.