Creation of an acidic metallosupramolecular architecture templated by a strong Brønsted acid (HClO4) and its reversible adsorption/release of ammonia molecules in aqueous media are reported. The 1:1 reaction of a digold­(I) metalloligand, [Au2(trans-dppee)­(d-Hpen)2] ([H2 1]), with Ni­(OAc)2 yielded a {AuI 2NiII} n 1D coordination polymer ([2]). A similar reaction with Ni­(ClO4)2 produced a AuI 4NiII 2 hexanuclear complex, which co-crystallized with HClO4 to form a metallosupramolecular structure in [3]·2HClO4; the metallosupramolecular structure consisted of {AuI 4NiII 2}6 octahedra and {ClO4 –}10 adamantanes, together with H3O+ ions. Compound [3]·2HClO4 was single-crystal-to-single-crystal converted to [3]·2NH4ClO4 via treatment with aqueous ammonia; its reverse conversion was achieved via treatment with aqueous perchloric acid.

We have examined the local 3d electronic structures of Co-Au multinuclear complexes with the medicinal molecules d-penicillaminate (d-pen) [Co{Au(PPh3)(d-pen)}2]ClO4 and [Co3{Au3(tdme)(d-pen)3}2] by Co L2,3-edge soft X-ray absorption (XAS) spectroscopy, where PPh3 denotes triphenylphosphine and tdme stands for 1,1,1-tris[(diphenylphosphino)methyl]ethane. The Co L2,3-edge XAS spectra indicate the localized ionic 3d electronic states in both materials. The experimental spectra are well explained by spectral simulation for a localized Co ion under ligand fields with the full multiplet theory, which verifies that the ions are in the low-spin Co 3+ state in the former compound and in the high-spin Co 2+ state in the latter.

The title compound, [Au2(C27H26P2)2][NiCl4]·C4H10O, consists of a digold(I) complex cation, an [NiCl4]2− complex anion and a diethyl ether solvent mol­ecule. Two 1,3-bis­(di­phenyl­phosphan­yl)propane (dppp) ligands bridge two AuI atoms, forming a metallacycle in which each of the AuI atoms is coordinated in a slightly distorted linear environment by two P atoms. In the complex anion, the NiII atom is coordinated by four chloride ligands in a distorted tetra­hedral geometry. The complex cation and the complex anion form a cation–anion pair through two Au⋯Cl contacts of 3.040 (1) and 3.021 (2) Å. One of the phenyl groups of the dppp ligand is disordered over two positions with equal occupancies.

A unique example of a coordination system that creates optically pure crystals from a meso compound with d- and l-amino acids is reported. The 1:1 reaction of a newly prepared meso digold(I) complex, [Au (dcpe)(d-Hpen)(l-Hpen)] ([H 1]), with Co(OAc) under aerobic conditions yielded a cationic Au Co trinuclear complex, [Au Co(dcpe)(d-pen)(l-pen)] [2] , in which [1] acts as a hexadentate-N ,O ,S metalloligand to a Co center. Similar reactions with M(OAc) (M=Ni and Zn) produced analogous but neutral Au M complexes, [Au M(dcpe)(d-pen)(l-pen)] ([3 ]). Complexes [2] and [3 ] are chiral (C vs. A) at the octahedral Co and M centers due to the arrangement of the N ,O ,S donor set. In addition, through spontaneous resolution, [3 ] gave optically pure C-[3 ] and A-[3 ] crystals, showing the creation of homochirality from meso-[1] and achiral M through crystallization. Such a phenomenon was not observed for [2] , which gave a racemic compound containing both C-[2] and A-[2] .

Optically pure crystals from a meso‐compound with d‐ and l‐amino acids have been created for the first time. The reactions of a meso‐digold(I) complex containing both d‐ and l‐penicillamine with MII (NiII, ZnII) yielded neutral AuI2MII complexes, which are chiral (C vs. A) at the metal centers. By spontaneous resolution, AuI2MII complexes gave optically pure C‐ and A‐crystals, showing the creation of homochirality from meso‐digold(I) complex and achiral M2+ through crystallization; that is the “Coordination Trick” in this case. Such a phenomenon has not been observed for cationic AuI2CoIII complex, giving a racemic compound containing both C‐ and A‐isomers. More information can be found in the Communication by T. Konno et al. on page 16438.