Nobuto Yoshinari

Formation, Expansion, and Interconversion of Metallarings in a Sulfur‐Bridged AuICoIII Coordination System

A novel Au(I) Co(III) coordination system that is derived from the newly prepared [Co(D-nmp)2 ](-) (1(-) ; D-nmp=N-methyl-D-penicillaminate) and a gold(I) precursor Au(I) is reported. Complex 1(-) acts as a sulfur-donating metallaligand and reacts with the gold(I) precursor to give [Au2 Co2 (D-nmp)4 ] (2), which has an eight-membered Au(I) 2 Co(III) 2 metallaring. Treatment of 2 with [Au2 (dppe)2 ](2+) (dppe=1,2-bis(diphenylphosphino)ethane) leads to the formation of [Au4 Co2 (dppe)2 (D-nmp)4 ](2+) (3(2+) ), which consists of an 18-membered Au(I) 4 Co(III) 2 metallaring that accommodates a tetrahedral anion (BF4 (-) , ClO4 (-) , ReO4 (-) ). In solution, the metallaring structure of 3(2+) is readily interconvertible with the nine-membered Au(I) 2 Co(III) metallaring structure of [Au2 Co(dppe)(D-nmp)2 ](+) (4(+) ); this process depends on external factors, such as solvent, concentration, and nature of the counteranion. These results reveal the lability of the AuS and AuP bonds, which is essential for metallaring expansion and contraction.

Synthesis, Structures, and Luminescence Properties of Interconvertible AuI2ZnII and AuI3ZnII Complexes with Mixed Bis(diphenylphosphino)methane and d-Penicillaminate

The reaction of the digold(I) complex [Au2(dppm)(D-pen)2](2-) ([1](2-); dppm = bis(diphenylphosphino)methane and D-pen = D-penicillaminate) with Zn(2+) in a 1:1 ratio gave the heterometallic Au(I)2Zn(II) trinuclear complex [Au2Zn(dppm)(D-pen)2] ([3]), in which the Zn(2+) ion is coordinated by [1](2-) in an N2O2S2 octahedral geometry with the trans(O) configuration, forming an 8-membered Au2ZnS2P2C metalloring. A similar reaction using the newly prepared and crystallographically characterized trigold(I) complex [Au3(dppm)2(D-pen)2](-) ([2](-)) produced the Au(I)3Zn(II) tetranuclear complex [Au3Zn(dppm)2(D-pen)2](+) ([4](+)), in which the Zn(2+) ion is coordinated by [2](-) in a similar octahedral geometry to form a Au3ZnS2P4C2 12-membered metalloring. Complex [3] was converted to [4](+) by treatment with [Au2(dppm)2](2+) in a 2:1 ratio, whereas [4](+) reverted to [3] upon treatment with a mixture of [Au(d-pen)2](2-) and Zn(2+) in a 1:1 ratio, indicative of the facile insertion/removal of the [Au(dppm)](+) moiety with retention of the geometry of the trans(O)-[Zn(D-pen-N,O,S)2](2-) unit. An analogous interconversion that requires the insertion/removal of the [Au(dppm)](+) moiety was also recognized between [1](2-) and [2](-). NMR spectroscopy revealed that [4](+) is in equilibrium with [3] and [Au2(dppm)2](2+) in solution, the ratio of which is largely dependent on the solvent polarity. The luminescence properties of these complexes were also investigated, revealing the importance of the intramolecular aurophilic interaction, as well as the Zn(II) coordination, for enhancement of the emission quantum efficiencies.

An Extremely Porous Hydrogen-Bonded Framework Composed of d-Penicillaminato Co(III)2Au(I)(3) Complex Anions and Aqua Cobalt(II) Cations: Formation and Stepwise Structural Transformation.

A unique example of a hydrogen-bonded ionic solid with a porosity of 80 %, [Co(H2O)6]3 [Co2Au3 (d-pen-N,S)6]2 (1; d-H2 pen=d-penicillamine), composed of [Co(H2O)6](2+) cations and [Co2Au3 (d-pen-N,S)6 ](3-) anions, is reported. Solid 1 was kinetically produced and was then transformed stepwise into two more thermodynamically stable solids with lower porosities, [Co(H2O)4 ][Co(H2O)6]2 [Co2Au3 (d-pen-N,S)6]2 (2) and [Co(H2O)4]3 [Co2 Au3 (d-pen-N,S)6]2 (3), through the coordination of the free carboxylate groups in [Co2Au3 (d-pen-N,S)6](3-) to Co(II) centers. Solids 1-3 were structurally characterized, and the selective adsorption of small molecules into their pores was investigated.

pH‐Controlled Multiple Chiral Inversion That Induces Molecular Dimerization in a Gold(I)–Cobalt(III) Coordination System with L‐Cysteinate

Herein, a unique coordination system that exhibits multiple chiral inversions and molecular dimerization in response to a subtle pH change is reported. Treatment of (Δ)2-H3[Au3Co2(L-cys)6] (H3[1 a]) with [Co3(aet)6](NO3)3 (aet=2-aminoethanethiolate) in water at pH 7 gave a 1:1 complex salt of [Co3(aet)6](3+) and [1 a](3-), retaining the Au(I)3Co(III)2 structure and chiral configurations of [1 a](3-). Similar treatment at pH 9 led to not only the inversion of all of the chiral Co(III) and S centers but also the dimerization of [1 a](3-), giving a 2:1 complex salt of [Co3(aet)6](3+) and (Λ)4(R)12-[Au6Co4(L-cys)12](6-) ([2](6-)). When dissociated from [Co3(aet)6](3+) in solution, [2](6-) was converted to (Λ)2(R)6-[Au3Co2(L-cys)6](3-) ([1 b](3-)) with retention of the chiral configurations.

A 1 : 1 intercluster compound consisting of +6 and −6 charged RhIII4ZnII4 octanuclear cations and anions with aminothiolate ligands

The first example of a 1 : 1 metal–organic intercluster compound with +6 charged cations and −6 charged anions was synthesized from [Zn4O{Rh(aet)3}4]6+ (aet = 2-aminoethanethiolate) and [Zn4O{Rh(L-cys)3}4]6− (L-cys = L-cysteinate). Its structure was determined by single-crystal X-ray crystallography, which revealed the formation of a diamondoid (dia) hydrogen-bonding network of the cluster anions, accommodating the cluster cations in its cavities.

A drastic change in the superhydrophilic crystal porosities of metallosupramolecular structures via a slight change in pH

A unique pH-controlled synthesis of two metallosupramolecular structures from CoAu complex anions and ZnII cations is reported. A dense coordination polymer (porosity ∼13%) was formed at a pH of 5.0, whereas a porous ionic framework (porosity ∼61%) that selectively adsorbs CO2 and H2O was created when the pH was adjusted to 5.5.

cis-Dichloridobis(2-phenyl-pyridine-κN)platinum(II).

In the title complex, cis-[PtCl2(C11H9N)2], the PtII ion is situated in a slightly distorted square-planar environment coordinated by two N atoms from two 2-phenylpyridine ligands and two Cl atoms. The two pyridyl planes are inclined with dihedral angles of 59.1 (2) and 61.84 (19)° with respect to the PtCl2N2 plane. In the crystal, the complex molecules display inter- and intramolecular π–π stacking interactions, with centroid-centroid distances of 3.806 (5)–3.845 (5) Å, which form a one-dimensional column structure along the a axis.

Chiral Scrambling and Independent Crystallization of d4, l4, and d2l2 Isomers of an AuI4CoIII2 Hexanuclear Complex with Mixed Penicillaminate and Bis(diphenylphosphino)ethane

The 1:1 mixing of a pair of enantiomers of a cyclic Au(I)4Co(III)2 hexanuclear complex having penicillaminate (pen) and 1,2-bis(diphenylphosphino)ethane (dppe), [Au4Co2(dppe)2(d-pen)4](2+) (d4-[1](2+)) and [Au4Co2(dppe)2(l-pen)4](2+) (l4-[1](2+)), in solution produced an additional stereoisomer, [Au4Co2(dppe)2(d-pen)2(l-pen)2](2+) (d2l2-[1](2+)), because of the scrambling of [Co(d-pen)2](-) and [Co(l-pen)2](-) units between d4-[1](2+) and l4-[1](2+). Upon crystallization with NO3(-), the three stereoisomers were independently crystallized to form three different kinds of crystals, homochiral crystals of d4-[1](NO3)2, homochiral crystals of l4-[1](NO3)2, and heterochiral crystals of d2l2-[1](NO3)2, showing a unique example of the self-recognition and organization of three stereoisomers upon crystallization.

Tetrapotassium [μ_2-N-carboxylato-D-penicillaminato(3-)-5:6κ^2S:S][μ_2-D-penicillaminato(1-)-2:3κ^2S:S]tetrakis[μ_2-D-penicillaminato(2-)]-1:2κ^3N,S:S;1:6κ^3N,S:S;3:4κ^3S:N,S;4:5κ^3N,S:S-2,3,5,6-tetragold(I)-1,4-dinickel(II) ethanol monosolvate decahydrate

In the crystal structure of the title compound, K(4)[Au(4)Ni(2)(C(6)H(8)NO(4)S)(C(5)H(9)NO(2)S)(4)(C(5)H(10)NO(2)S)].C(2)H(6)O.10H(2)O, (I), two planar [Ni(C(5)H(9)NO(2)S)(2)](2-) units are spanned by [Au(2)(C(5)H(10)NO(2)S)](+) and [Au(2)(C(6)H(8)NO(4)S)](-) linkers through S atoms, forming an S:S-bridged Au(I)(4)Ni(II)(2) hexanuclear complex anion. One of six organic ligands in the complex anion is a carbamino derivative of D-penicillamine (3-mercaptovaline) and the others are deprotonated D-penicillamines. Each complex anion binds to nine K(+) ions through six carboxylate and one carbamino groups to construct a three-dimensional structure.

Valence Interconversion of Octahedral Nickel(II/III/IV) Centers

Three oxidation states (+2, +3, +4) of an octahedral nickel center were stabilized in a newly prepared RhNiRh trinuclear complex, [Ni{Rh(apt)3 }2 ]n+ (apt=3- aminopropanethiolate), in which the nickel center was bound by six thiolato donors sourced from two redox-inert fac-[RhIII (apt)3 ] octahedral units. The three oxidation states of the octahedral nickel center were fully characterized by single-crystal X-ray crystallography, as well as spectroscopic, electrochemical, and magnetic measurements; all three were interconvertible, and the conversion was accompanied by changes in color, magnetism, and Jahn-Teller distortion.