Cyclometalated platinum(Ⅱ) complexes with sterically bulky camphor-derived groups as β-diketonate ancillary ligand:a new route to efficiently reducing π-π interactions and Pt-Pt interactions

A new series of mono-cyclometalated square planar platinum(Ⅱ) complexes have been synthesized and the single-crystal X-ray structures of complex 1 and 2 have been determined.The complexes have the general formula ppyPt(O^O),where ppy is 2-phenylpyridyl,and O^O is β-diketonate ancillary ligands with the acyl substituent group in position 3 of(D)-(+)-camphor.Although,like the many Pt(Ⅱ) complexes with square-planar geometry,these complexes have plane stacking modes in crystal structure,the sterically bulky ca...     

Synthesis and Crystal Structure of cis—[meso—1,3—Bis（propylsulfinyl）propane]dichloroplatinum（Ⅱ）

1 INTRODUCTION A number of Pt complexes with monosulfoxide have been isolated and characterized[1]. It was indicated that the sulfoxide group trends to coordinate to soft metals (Pt, Pd, etc.) by its sulfur atom[2]. Pt(Ⅱ) trends to bond to disulfoxides in cis-mode and such complexes have potential antitumor activity[2]. However, only few examples of such complexes have been structurally characterized[3]. We will report herein the crystal structure of a new Pt(Ⅱ) complex with a disulf…     

Synthesis and Crystal Structure of cis-[1,2-Bis(phenyl-thiomethyl)benzene]dichloroplatinum(Ⅱ)·0.5acetonitrile

1 INTRODUCTION The coordination chemistry of bithioethers with noble metal ions has received considerable attention for a very long time due to their appli- cations in extracting noble metals. A number of Pt(Ⅱ) complexes with such ligands have been reported[1～7], among which some crystal structures have been determined[4～7]. However, most of these structures are Pt(Ⅱ) complexes of a few bithioether ligands with flexible alkyl spacers, RS(CH2)nSR. To our knowledge, the crystal str…     

The Synthesis of Glycosyl Phosphite-Pt(II) Complexes

Sugar derivatives whose molecules contain trivalent phosphorus groups have been coming into use for different scientific purposes, including the synthesis of metal com- plexes. These metal complexes of glycosyl phosphites are effective chiral catalysts in enantioselective synthesis1-5such as hydrogenation, cyclopropylation, hydro phosphina- tion and hydrosilylation of achiral olefin. Furthermore, this kind of compounds are also widely applied in biology and medicine area and open up a new fie…     

Studies of the Intramolecular Aromatic-ring Stacking Interactions in the Ternary Platinum（Ⅱ） Complexes

The stability constants of some ternary mixed-ligand complexes, Pt (Phen)(CA) , where Phen-1,10-phenanthroline and CA^-=carboxylate, were determined by means of potentiometric pH titration in aqueous solutions (I=0. 1mol/L, KNO3; 25℃), and the stability of them was compared with that of the corresponding binary complexes. It was revealed that the ternary complexes containing phenylalkane carboxylates ligands (PCA-) are much more stable than those formed with formate and acetate. The results indicate that there exist the intramolecular aromatic-ring interactions between the phenanthroline ring of Phen and the phenyl moiety of ligand PCA- in the ternary mixed-ligand Pt(Phen) (PCA)^- complexes. The extent of the stacking interactions, which depends on the number of methylene groups between the phenyl moieties and the coordinated phenylalkane carboxylate groups, was calculated. The best-fitted stack was obtained for the complexes with 2-phenylacetate and 3-phenylpropionate as the ligands.     

Tuning the Excited State of Tetradentate Pd(ll) and Pt(ll) Complexes through Benzannulated N-Heteroaromatic Ring and Central Metal

A series of tetra de ntate Pd(ll)and Pt(ll)complexes containing fused 5/6/6 metallocycles with phe nyl/V-heteroaromatic ben-zo[d]imidazole(pbiz),benzo[d]oxazole(pboz)or benzo[d]thiazole(pbthz)-containing ligands was developed.Systematic studies by experiments and theoret:ical calculations reveal that both the central metal and the benzannulated A/-heteroaromatic ring have sig-n ificant in flue nee on the electrochemical,photophysical and excited-state properties of the Pd(ll)and Pt(ll)complexes.In identical condition,compared to pb/z-based Pd(ll)and Pt(ll)complexes,the corresponding metal complexes with pboz and pbthz-containing ligand show significant red-shift emission spectra.     

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.     

Theoretical Studies on the Excited-state Properties of Ru(Ⅱ) Polypyridyl Complexes

Using DFT/TDDFT methods,the excited-state lifetimes of Ru(Ⅱ) polypyridyl complexes were computed accurately and the reason of Ru(Ⅱ) polypyridyl complexes with long excited-state lifetimes was explained by the electron-transfer distances and HOMO-LUMO gaps.Finally,the photovoltaic conversion efficiencies of complexes were predicted using DFT and docking methods.This work has provided methods of predicting the excited-state lifetimes and photovoltaic conversion efficiencies of Ru(Ⅱ) polypyridyl complexes.     

Preparation of Platinum(II) Complexes with 1-β-D-Ribofuranosyl-1,2,4-triazole-3-carboxamide and its Deoxy-analogue

Much attention is currently focused on the design of new generations of platinum anti-cancer complexes to prevent resistance of cisplatin. We have developed a new platinum-based antitumor agent with broad-spectrum antiviral activity. The cis-[Pt(DMSO)2Cl2] and K[Pt (DMSO) Cl3] reacted with 1-??-D-ribofuranosyl-1,2,4-triazole-3-carboxamide (ribavirin) and its deoxy-analogue (deoxyribavirin) to give the coordinated complexes which exhibited activity against both DNA and RNA viruses1. The…     

DFT study on second-order nonlinear optical properties of Pt (Ⅱ) complexes with different chromophores

DFT B3LYP/LANL2DZ method was employed to calculate electron properties and the second-order nonlinear optical(NLO) respond of platinum(Ⅱ) complexes which have been synthesized by Weinstein group.4,7-diphenyl-1,10-phenanthroline shows the ability to push electron in these complexes.Metal Pt plays a balancing charge role.Comparing complex 1b-6b with complex a,the βvec value of complex 1b-5b is larger than one of complex a,while the βvec value of complex 6b is smaller than one of com-plex a.In these seven comp...     

TERNARY Cu(Ⅱ)(ATP)AND HETEROAROMATIC N BASE COMPLEXES IN SOLUTION:STABILITY CONSTANTS AND ANTITUMOR MECHANISM EXPLORATION

The stability of the complexes of four pyridine-like ligandswith Cu(ATP)~(2-) was studied and by comparing the stability constants of theternary complexes[Cu(ATP)L]~(2-) with those of the binary complexes[CuL]~(2+),astacking interaction between the pyridine ring and the purine ring of ATP isindicated.It is possible to interpret the antitumor mechanism of[Pt(NH_3)_8(N-het)Cl]Cl in terms of this stacking interaction.     

SYNTHESES AND MOLECULAR STRUCTURES OF THE ASYMMETRICAL DIPHOSPHINE LIGANDS AND THEIR Pt, Ni ORGANOMETALLIC COMPLEXES

In this paper, we report a novel two-step synthetic method of the symmetrical and asymmetrical diphosphine ligands 1, 2-bis(ditertbutylphosphino)ethane and 1, 2-bis(phenyltertbutylphosphino) ethane, and simultaneously establish a novel synthetic method of diphosphine ligand 1, 4-bis(phosphinocyclopentyl)butane with larger chelate ring. The former was prepared from the reaction of 1, 2-bis(dichlorophosphino)ethane with Grignard reagent andalkyl lithium, respectively, the latter from the reaction of 1, 4-di-Grignard reagent with PCl_3. Furthermore, a series of organometallic complexes of Pt, Ni containing diphosphine chelate ligand were prepared from the reaction of (COD) PtCl_2 complex with diphosphine. These complexes are very stable. Among these complexes, the molecular structures of (d(t-Bu)pe)-PtCl_2, (dPCypb)PtCl_2 and ((n-Bu) (PCyp))_2PtCl_2 complexes have been determined by X-ray diffraction method indicating they are novel complexes. The influence of diphosphine ligand on the molecular structure     

STUDIES ON STRUCTURES OF SOME PLATINUM COMPLEXES WITH 1, 1-CYCLOPROPANEDICAR BOXYLATE

The crystal structure, of [Pt(NH_3)_2CPrDCA]. H_2O (Ⅰ), [Pt(CH_3NH_2)_2CPrDCA] (Ⅱ), and [Pt(dmbn) CPrDCA]·2.5H_2O(Ⅲ) (where CPrDCA is 1, 1-cyclopropanedicarboxylate; dmbn is 2, 3-dimethyl-2, 3-butyldiamine) are determined. Compound Ⅰ crystallizes in the orthorhombic space group P_(nma) with the cell dimensions: a=6.517(2), b=9.709(3), c=14.205(5), Z=4, R=0.058. Compound Ⅱ is monoclinic with space group P2_1/n, a=9.648(3), b=8.720(2), c=12.770(4), β=107.12(2), Z=4, R=0.059. Compound Ⅲ belongs to the monoclinic system space group P2_1/m with the cell dimensions: a=6.494(1), b=19.638(3), c=6.606(1), β=94.44(1), Z=2, R=0.038.Electronic structures of the complexes are studied and the correlstion between structure of the amine ligands and biological activity of the complexes is explored.     

Studies on Polymeric Crown Ethers (Ⅰ)——The Syntheses and Complexation Properties of Polymeric Thiacrown Ethers with Polyether Backbone

Four new polymeric oxa-thiacrown ethers were prepared by the intramolecular cy-clization of poly (2-chloroethylglycidyl ether) with dimercaptans, which is the most convenient method for synthesizing poly(thiacrownether)s. The poly(thiacrownether)s exhibited excellent complexation properties for noble metal ions such as Au ( Ⅲ ) , Pd ( Ⅱ ) and Ag( Ⅰ ) , except Pt( Ⅳ ). In addition, the XPS of polymeric thiacrown ether (PC3) and its complexes of Au( Ⅲ ) and Pd( Ⅱ ) were determined.     

Polymerization of lactic <Emphasis Type="Italic">O</Emphasis>-carboxylic anhydride using organometallic catalysts

The ring-opening polymerization of 5-methyl-1,3-dioxolane-2,4-dione(lactic O-carboxylic anhydride,LacOCA) using organometallic complexes,including Co(Ⅲ) complexes with Schiff base ligands,Tin(Ⅱ) alphatates and Al(Ⅲ) complexes with Schiff base ligands,was explored.The polymerization was carried out by treatment of the organometallic complexes with LacOCA in toluene under mild conditions.The corresponding poly(lactic acid) was characterized by spectroscopy and thermal analyses,which revealed insight into the structure of the effective catalyst for the polymerization of LacOCA.     

STRUCTURAL CHARACTERS OF SEVERAL Pt (Ⅱ) COMPLEXES CONTAINING BULKY PHOSPHINE LIGANDS PR_3(R = Ph or Cyclo-hexyl, C_6H_(11))

<正> The main structural features of the five Pt(Ⅱ ) complexes containing two PR3 ligands are summarized. The influence of the interaction of the different ligands on the coordination structures is preliminary discussed.     

Investigation of Absorption Spectra of Bis(alkylxanthato)-platinum(Ⅱ) Complexs

Being widely used as good ligands,xanthates and related compounds have been extensively investigated.However,reports on Pt(Ⅱ) xanthates have been sparse so far.Watt et al.reported the synthesis and characterization of Pt(S_2COR)_2(R=Me,Et),but did not provide any absorption spectra of these complexes.We prepared twelve platinum (Ⅱ) xanthate complexes and examined their absorption spectra in detail.     

Unprecedented 1D Mixed-metal Polynuclear Cyclometalated Platinum Complexes： Synthesis, Structural Characterization and Spectroscopic Properties

The complexes [Pt2L2（μ-dppm）]（ClO4）2 （1） and {[Pt2L2（μ-dppm）Li（CH3CN）2]（ClO4）3}n （2）, where HL is 6-[4-（diethoxyphosphorylmethyl）phenyl]-2,2′-bipyridinyl and dppm is bis（diphenylphosphino）methane, have been synthesized and characterized. In complex 1 the platinum（Ⅱ） center adopts a distorted square planar coordination geometry. The polymer 2 exhibits a ＂stairstep＂ configuration with one-dimensional Pt（Ⅱ）N^N^CPO- Li（Ⅰ）-OPC^N^ NPt（Ⅱ） mixed-metal units which are linked through dppm. Both complexes have metal-metal interaction with Pt- Pt distances of 3.325（2） and 3.1432（9） A, respectively, and display strong metal-metal-to-ligand charge-transfer （MMLCT） triplet state emission. The density-functional-theory calculation was used to interpret the absorption spectra of the complexes.     

Photoacoustic imaging-guided chemo-photothermal combinational therapy based on emissive Pt(Ⅱ)metallacycle-loaded biomimic melanin dots

Pt(Ⅱ)-based metallacycles,as an important family of supramolecular coordination complexes(SCCs),have exhibited excellent antitumor activity at the cell level.However,the biomedical applications of Pt(Ⅱ)-based metallacycles for animal studies are still hindered by their poor stability,non-targeted tumour,and lack of detectable feedback for evaluating therapeutic progress.Herein,we propose a strategy that introduces melanin dots as a biomedical platform to load bright-emission Pt(Ⅱ)-based metallacycles,thereby constructing a theranostic agent that enables photoacoustic imaging(PAI)-guided chemo-photothermal combinational therapy.Melanin dots act as a protective carrier to preserve the integrity of Pt(Ⅱ)-based metallacycles before uptake by tumour tissues.Meanwhile,the PAI signal from melanin dots furnishes more comprehensive information on the tumour.Moreover,the heat generated after NIR laser irradiation can not only trigger the apoptosis of tumour cells but also promote the deeper penetration of Pt(Ⅱ)-based SCCs into tumour tissue,thus enhancing the efficiency of chemotherapy.     

Molecular design and theoretical investigation into one-and two-photon absorption properties of two series of cyclometalated platinum(Ⅱ) complexes

We have theoretically investigated two series of cyclometalated Pt(Ⅱ) complexes,a series [Pt(C,N,N) Cl] and b series [Pt(C,N,Npyrazolyl) Cl].The geometrical and electronic structures are calculated at the ECP60MWB//6-31G*(H,C,Cl,N,S) basis set level using DFT method;one-photon absorption(OPA) properties are calculated by using both TDDFT and ZINDO methods and two-photon absorption(TPA) properties are obtained with the ZINDO/SOS method.The resonance integrals parameters(βsp and βd) for Pt are adjusted to -1 and -28.5 eV,respectively,to make max OPA wavelength calculated by ZINDO closest to the experimental data and TDDFT results.The calculated results indicate the molecule 2b([Pt(Cnaphthyl,N,Npyrazolyl) Cl]) has the biggest potential as outstanding TPA materials because(i) the TPA properties of b series are more outstanding in IR wavelength range,the molecules in b series have good transparencies and possess 1-pyrazolyl-NH that is also available for another metal coordination(e.g.,dimerization) and chemical interactions;(ii) when C is Cnaphthyl in the C,N,N ligand of cyclometalated Pt(Ⅱ) complexes,the molecules have the best conjugation effect and the best TPA properties.