Multiresponsive,easy-reversible,and dual-visual Pt(Ⅱ)salt nanostructures for advanced anti-counterfeiting application

Smart materials that integrate multi-stimuli response,full reversibility,and dual-visual read-out channel are highly desired for anticounterfeiting and information encryption applications.Herein,we developed a multiresponsive perchlorate terpyridyl Pt(Ⅱ)nano complex which could undergo fully reversible conversion between three forms stimulated by water or formaldehyde molecule due to the extent of Pt–Pt interaction.Meanwhile,a dual-visual channel,i.e.,the colorimetric channel changed from yellow to orange or red and the corresponding luminescent channel from orange to orange-red or red,has also been found.The weak and equivalent strength of ion-dipole interaction and hydrogen bond that generated between formaldehyde/water and Pt(II)salt result in the easy-control reversibility between the three forms.Furthermore,by introducing different polymer matrices,1Cl·ClO_(4)@PMMA(1Cl·ClO_(4):[Pt(tpy)Cl]·ClO4,tpy:2,2':6',2''-terpyridine),PMMA:poly(methyl methacrylate))and 1Cl·ClO4@PVA(PVA:polyvinyl alcohol)are successfully constructed,which exhibit different reversible behaviors since the PMMA and PVA matrix exert different influences on the strength of hydrogen-bond.Those smart Pt(II)salt nanostructures present great potential for high-security-level anticounterfeiting application.

An AIPE-active fluorinated cationic Pt(Ⅱ)complex for efficient detection of picric acid in aqueous media

A novel cationic Pt(Ⅱ)complex 2 with 2-(2,4-difluorophenyl)pyridine as the cyclometalating ligand and 1,10-phenanthroline as the auxiliary ligand has been synthesized and fully characterized.This complex exhibits much higher aggregation-induced phosphorescent emission activity than that of a nonfluorinated complex 1 in CH_(3)CN/H_(2)O.The complex 2 demonstrates efficient detection on picric acid(PA)in CH_(3)CN/H_(2)O,providing a high quenching constant(K_(SV)=2.3×10^(4) L/mol)and a low limit of detection(LOD=0.26μmol/L).In addition,complex 2 shows high selectivity for detection of PA in real water samples.Density functional theory calculations and proton nuclear magnetic resonance spectra suggest that the detection mechanism is attributed to the photo-induced electron transfer.

A STUDY OF SILICA-SUPPORTED CROSS-LINKED POLY (MALEIC ACID-CO-STYRENE)-PLATINUM COMPLEX IN THE HYDROGENATION OF p-CRESOL

A silica-supported cross-linked poly(maleic acid -co- styrene)-platinum complex (PMS-Pt) has been prepared and found to be active in the hydrogenation of p-cresol under mild conditions (303-323K, 1.01 x 10(5)Pa). In this hydrogenation system water serves as a solvent and p-cresol can be converted to 4-methylcyclohexanol quantitatively via 4-methylcyclohexanone as intermediate.

Synthesis,Characterization and Catalytic Hydrosilylation Activity of [60] Fullerene n-Propylamine Platinum,Rhodium Complex

Fullerene n propylamine platinum,rhodium complex have been prepared from C 60 via amination with n propylamine, then reacting respectively with potassium chloroplatinite or rhodium chloride. The two noble metal complexes can effectively catalyze hydrosilylation of olefins with triethoxysilane. The Pt complex exhibits high regioselectivty for styrene, nearly 100% branched product is obtained.

Synthesis and Structure of bc-Dichloro-af-dihydroxo-de-bis(N-3-pyridinylmethanesulfonamide)platinum(Ⅳ) Diydrate

The Pt（IV） complex cis,cis,trans-[Pt（PMSA）2Cl2（OH）2]·2H2O（1）, where PMSA = N-3-pyridinylmethanesulfonamide, has been synthesized and characterized by elemental analysis, molar electric conductivity and IR spectrum. X-ray crystallography revealed that the title compound crystallizes in the monoclinic C2/c space group with unit cell dimensions a = 16.5424（7）, b = 8.6973（3）, c = 16.6079（6） A, β = 117.185（5）° and Z = 4. Pt（IV） has an octahedral coordination geometry and the PMSA ligands are coordinated via the pyridine N atom. They are in a transoid orientation between each other and are inclined in the same direction with respect to the Pt-C1-Cli-N-Ni plane at an angle of 64.6（1）° （symmetry operation： （i） 1- x, y, 3/2-z）. The structure is stabilized by a system of hydrogen bonds involving the complex and water molecules.

Variance of Solid-state Pt…Pt Interactions in Luminescent Cyclometalated Cationic Pt(Ⅱ)-isocyanide Complexes

Polymorphic structures of cyclometalated cationic Pt(Ⅱ)-isocyanide complexes(-)-1[Pt((−)-NNC)(Dmpi)]Cl with different packing modes can be isolated before.In this paper,a series of solid-state powders with variable colors(yellow,orange and red)have been obtained from the evaporation of complex(-)-1 in different solvents.The crystallinity,thermogravimetric properties,absorption,luminescence and excited state lifetimes have been studied.In addition,intermolecular Pt…Pt interactions in the optimized configurations of different aggregates have been explored,and calculations of frontier molecular orbitals of monomer,dimer,trimer and tetramer have been carried out.

Synthesis,Crystal Structure and Luminescent Mechanochromism of a Square-planar Pt(Ⅱ) Complex Based on 1,10-Phenanthroline Derivative

A new square-planar platinum(Ⅱ) complex, [Pt(Me3SiC≡Cphen)(C≡CC6H4Cl-3)2](1), was synthesized by using 3-trimethylsilylethynyl-1,10-phenanthroline(Me3SiC≡Cphen) and 3-chlorophenylacetylene ligands, and its structure was characterized by single-crystal X-ray crystallography. 1 crystallizes in triclinic, space group P1 with a = 6.9524(5), b = 12.7796(11), c = 17.5846(10) ?, α = 78.484(5), β = 88.700(5), γ = 75.600(6)°, V = 1482.23(19) ?3, Z = 2, C33H24Cl2N2 PtSi, Mr = 742.62, Dc = 1.664 g/cm3, F(000) = 724, μ(Mo Ka) = 4.979 mm-1, R = 0.0369 and wR = 0.0786. In 1, adjacent molecules along the a axis are stacked in a columnar structure through π···π interactions, and such neighboring columnar structures are connected with each other by C–H···π hydrogen bonds to form a 2D supramolecular network. 1 exhibits reversible luminescence mechanochromic property with the luminescence red shift in a range of ca. 146~182 nm. Extremely large red-shifts of luminescence spectra suggest that luminescent mechanochromic property of 1 is due to the formation of aggregate via Pt–Pt interaction during the mechanical grinding. Based on this property, a simple device was developed and used for rewritable data storage.

TD-DFT Studies on Electronic and Spectral Properties of Platinum（II） Complexes with Phenol and Pyridine Groups

The molecular structures of the ground and the lowest triplet states for a series of Pt（ll） complexes PtLCl（l）[L=6-（2-hydroxyphenyl）-2,2＇-bipyridine], Pt（pp）2[pp=2-（2-hydroxyphenyl）pyridine]（2）, PtbpyClz（bpy=2,2＇- bipyridine）（3）, and the free tridentate L ligand（4） were optimized by the density functional theory B3LYP and UB3LYP methods, respectively. On the basis of optimized geometries, the spectral properties were investigated with time-dependent density functional theory（TD-DFT）. In comparison with those of complexes 2 and 3, the more rigid structure of complex 1 together with its low rate of the radiationless decay via nonemissive d-d state leads to higher photoluminescence quantum efficiency. And the phosphorescence quantum efficiency of complex 1 can be easily controlled by modifying auxiliary ligands. The introduction of fluorine ligand into complexes can effectively increase the radiation transition rate and decrease the radiationless d-d transition rate, and as a result, a novel complex PtLF（5） might be a good phosphorescent material suitable for organic electronic devices.

Controlling Molecular Packing in Aqueous Metallosupramolecular Self-assembly by Ligand Geometry

The coordination geometry of d8 transition metal complexes has been successfully exploited as a tool to tune photophysical properties and self-assembly pathways of supramolecular polymerization processes,with a focus being primarily placed on organic media.Expanding such controlled supramolecular and photophysical properties to assemblies in aqueous media by molecular design is,however,still challenging due to the difficulty in programming noncovalent interactions in water.Herein,we tackle this challenge by analyzing the aqueous self-assembly of amphiphilic Pt(II)complexes of different molecular geometry in order to control self-assembly and metal−metal interactions in aqueous media.To this end,we have designed two Pt(II)complexes,1 and 2,containing an identical oligophenyleneethynylene(OPE)-based aromatic scaffold that differ in the molecular geometry(linear vs V-shaped)imposed by ligand substitution and studied their comparative self-assembly behavior in aqueous media.Even though both molecules follow the isodesmic mechanism of self-assembly,their structural difference strongly influences the molecular packing in aqueous media,which in turn impacts the photophysical properties(i.e.absence or presence of MMLCT)and the self-assembly outcome.While the molecular geometry for 2 enforces short Pt…Pt contacts driven by an efficient face-to-face stacking of the OPE backbone,the antiparallel packing of 1 with slight translational offset does not allow the formation of short Pt…Pt contacts.Such a distinct interplay of interactions for 1 and 2 in aqueous media leads to significant differences in photoluminescence.