5 research outputs found
Synthesis and Coordination Behavior of a Bipyridine Platinum(II) Complex with Thioglucose
A mononuclear platinum(II) complex
with two monodentate-<i>S</i> H<sub>4</sub>tg<sup>–</sup> ligands, [Pt(H<sub>4</sub>tg-κ<i>S</i>)<sub>2</sub>(bpy)] (<b>1</b>), was newly synthesized by the reaction of
[PtCl<sub>2</sub>(bpy)] (bpy = 2,2′-bipyridyl) with NaH<sub>4</sub>tg (NaH<sub>4</sub>tg =1-thio-β-d-glucose sodium
salt) in water. Complex <b>1</b> reacted with additional [PtCl<sub>2</sub>(bpy)] in water to give an S-bridged dinuclear complex, [Pt<sub>2</sub>(μ<sub>2</sub>-H<sub>4</sub>tg-κ<sup>1</sup><i>S</i>:κ<sup>1</sup><i>S</i>)<sub>2</sub>(bpy)<sub>2</sub>]<sup>2+</sup> ([<b>2</b>]<sup>2+</sup>), in which a
square-planar [Pt(H<sub>4</sub>tg)<sub>2</sub>(bpy)] unit binds to
a [Pt(bpy)]<sup>2+</sup> moiety through two thiolato groups. Treatments
of <b>1</b> with Cu<sup>2+</sup> and Ni<sup>2+</sup> in water
in the presence of bpy produced S-bridged dinuclear complexes [PtCu(μ<sub>2</sub>-H<sub>4</sub>tg-κ<sup>1</sup><i>S</i>:κ<sup>2</sup><i>O</i>,<i>S</i>)<sub>2</sub>(bpy)<sub>2</sub>]<sup>2+</sup> ([<b>3</b>]<sup>2+</sup>) and [PtNi(μ<sub>2</sub>-H<sub>4</sub>tg-κ<sup>1</sup><i>S</i>:κ<sup>2</sup><i>O</i>,<i>S</i>)<sub>2</sub>(bpy)<sub>2</sub>]<sup>2+</sup> ([<b>4</b>]<sup>2+</sup>), respectively,
in which a square-planar [Pt(H<sub>4</sub>tg)<sub>2</sub>(bpy)] unit
binds to a [M(bpy)]<sup>2+</sup> (M = Cu<sup>II</sup>, Ni<sup>II</sup>) moiety through two thiolato and two hydroxyl groups to form a chiral
[M(N)<sub>2</sub>(O)<sub>2</sub>(S)<sub>2</sub>] octahedron with the
Δ configuration. On the other hand, similar treatment with Cd<sup>2+</sup> in the presence of bpy resulted in the formation of an S-bridged
trinuclear complex, [Cd{Pt(μ<sub>2</sub>-H<sub>4</sub>tg-κ<sup>1</sup><i>S</i>:κ<sup>2</sup><i>O</i>,<i>S</i>)(μ<sub>2</sub>-H<sub>4</sub>tg-κ<sup>1</sup><i>S</i>:κ<sup>1</sup><i>S</i>)(bpy)}<sub>2</sub>]<sup>2+</sup> ([<b>5</b>]<sup>2+</sup>), in which each
of two square-planar [Pt(H<sub>4</sub>tg)<sub>2</sub>(bpy)] units
binds to a Cd<sup>II</sup> ion through two thiolato groups and one
hydroxyl group to form a chiral [Cd(O)<sub>2</sub>(S)<sub>4</sub>]
octahedron with the Λ configuration. Of two geometrical configurations,
syn and anti, which arise from the relative arrangement of two β-D-pyranose
moieties, [<b>2</b>]<sup>2+</sup> adopts the syn configuration
with symmetric bridging sulfur atoms, while [<b>3</b>]<sup>2+</sup>, [<b>4</b>]<sup>2+</sup>, and [<b>5</b>]<sup>2+</sup> all have the anti configuration with <i>R</i> configurational
bridging sulfur atoms. All of the complexes were fully characterized
by electronic absorption, CD, and NMR spectroscopies, along with single-crystal
X-ray crystallography
Water-Molecule-Driven Vapochromic Behavior of a Mononuclear Platinum(II) System with Mixed Bipyridine and Thioglucose
A mononuclear platinum(II) complex
with mixed bpy and H<sub>4</sub>tg<sup>–</sup> ligands, [Pt(H<sub>4</sub>tg-<i>S</i>)<sub>2</sub>(bpy)]·2H<sub>2</sub>O (<b>1a</b>; bpy = 2,2′-bipyridine and H<sub>5</sub>tg = 1-thio-β-d-glucose), is photoluminescent in the
solid state and undergoes facile and reversible removal of solvated
water molecules accompanied by changes in its absorption and emission
wavelengths. The analogous dmbpy complex, [Pt(H<sub>4</sub>tg-<i>S</i>)<sub>2</sub>(dmbpy)]·H<sub>2</sub>O (<b>2a</b>; dmbpy = 4,4′-dimethyl-2,2′-bipyridine), is also emissive
in the solid state, but its absorption and emission spectra remain
unchanged after dehydration. X-ray crystallographic analyses revealed
that the difference in the chromism of <b>1a</b> and <b>2a</b> is due to the difference in their hydrogen-bonding networks, which
involve solvated water molecules
Chiral Scrambling and Independent Crystallization of d<sub>4</sub>, l<sub>4</sub>, and d<sub>2</sub>l<sub>2</sub> Isomers of an Au<sup>I</sup><sub>4</sub>Co<sup>III</sup><sub>2</sub> Hexanuclear Complex with Mixed Penicillaminate and Bis(diphenylphosphino)ethane
The 1:1 mixing of a pair of enantiomers
of a cyclic Au<sup>I</sup><sub>4</sub>Co<sup>III</sup><sub>2</sub> hexanuclear complex having penicillaminate (pen) and 1,2-bis(diphenylphosphino)ethane
(dppe), [Au<sub>4</sub>Co<sub>2</sub>(dppe)<sub>2</sub>(d-pen)<sub>4</sub>]<sup>2+</sup> (d<sub>4</sub>-[<b>1</b>]<sup>2+</sup>) and [Au<sub>4</sub>Co<sub>2</sub>(dppe)<sub>2</sub>(l-pen)<sub>4</sub>]<sup>2+</sup> (l<sub>4</sub>-[<b>1</b>]<sup>2+</sup>), in solution produced an additional
stereoisomer, [Au<sub>4</sub>Co<sub>2</sub>(dppe)<sub>2</sub>(d-pen)<sub>2</sub>(l-pen)<sub>2</sub>]<sup>2+</sup> (d<sub>2</sub>l<sub>2</sub>-[<b>1</b>]<sup>2+</sup>), because of the scrambling of [Co(d-pen)<sub>2</sub>]<sup>−</sup> and [Co(l-pen)<sub>2</sub>]<sup>−</sup> units between d<sub>4</sub>-[<b>1</b>]<sup>2+</sup> and l<sub>4</sub>-[<b>1</b>]<sup>2+</sup>. Upon crystallization
with NO<sub>3</sub><sup>–</sup>, the three stereoisomers were
independently crystallized to form three different kinds of crystals,
homochiral crystals of d<sub>4</sub>-[<b>1</b>](NO<sub>3</sub>)<sub>2</sub>, homochiral crystals of l<sub>4</sub>-[<b>1</b>](NO<sub>3</sub>)<sub>2</sub>, and heterochiral crystals
of d<sub>2</sub>l<sub>2</sub>-[<b>1</b>](NO<sub>3</sub>)<sub>2</sub>, showing a unique example of the self-recognition
and organization of three stereoisomers upon crystallization
Anion-Controlled Assembly of Four Manganese Ions: Structural, Magnetic, and Electrochemical Properties of Tetramanganese Complexes Stabilized by Xanthene-Bridged Schiff Base Ligands
The reaction of manganese(II) acetate with a xanthene-bridged
bis[3-(salicylideneamino)-1-propanol]
ligand, H<sub>4</sub>L, afforded the tetramanganese(II,II,III,III)
complex [Mn<sub>4</sub>(L)<sub>2</sub>(μ-OAc)<sub>2</sub>],
which has an incomplete double-cubane structure. The corresponding
reaction using manganese(II) chloride in the presence of a base gave
the tetramanganese(III,III,III,III) complex [Mn<sub>4</sub>(L)<sub>2</sub>Cl<sub>3</sub>(μ<sub>4</sub>-Cl)(OH<sub>2</sub>)], in
which four Mn ions are bridged by a Cl<sup>–</sup> ion. A pair
of L ligands has a propensity to incorporate four Mn ions, the arrangement
and oxidation states of which are dependent on the coexistent anions
Anion-Controlled Assembly of Four Manganese Ions: Structural, Magnetic, and Electrochemical Properties of Tetramanganese Complexes Stabilized by Xanthene-Bridged Schiff Base Ligands
The reaction of manganese(II) acetate with a xanthene-bridged
bis[3-(salicylideneamino)-1-propanol]
ligand, H<sub>4</sub>L, afforded the tetramanganese(II,II,III,III)
complex [Mn<sub>4</sub>(L)<sub>2</sub>(μ-OAc)<sub>2</sub>],
which has an incomplete double-cubane structure. The corresponding
reaction using manganese(II) chloride in the presence of a base gave
the tetramanganese(III,III,III,III) complex [Mn<sub>4</sub>(L)<sub>2</sub>Cl<sub>3</sub>(μ<sub>4</sub>-Cl)(OH<sub>2</sub>)], in
which four Mn ions are bridged by a Cl<sup>–</sup> ion. A pair
of L ligands has a propensity to incorporate four Mn ions, the arrangement
and oxidation states of which are dependent on the coexistent anions