Metallointercalation reagents. Synthesis, characterization, and structural properties of thiolato(2,2',2''-terpyridine)platinum(II) complexes

Jennette, K. W.; Gill, J. T.; SADOWNICK, J. A.; Lippard, Stephen J.

doi:10.1021/ja00436a016

Cited by 263 publications

(168 citation statements)

References 9 publications

(13 reference statements)

Supporting

Mentioning

153

Contrasting

Order By: Relevance

“…The electronic absorption spectra of alkynylplatinum(II) terpyridine molecular rectangles 1−4 in dichloromethane solution at room temperature displayed intense intraligand [π → π*] transitions of the terpyridine and the alkynyl ligands at 250−345 nm together with the moderately intense absorptions at 420−490 nm, which are assigned as admixtures of metal-to-ligand charge transfer (MLCT) [dπ(Pt) → π*(terpyridine)] and ligand-to-ligand charge transfer (LLCT) [π(C≡CR) → π*(terpyridine)] transitions according to previous spectroscopic studies on alkynylplatinum(II) terpyridine systems (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28). Molecular rectangles 1−4 in degassed acetonitrile solution and solid state at 298 K exhibited structure-less emission bands at 620−700 nm, which are tentatively assigned as originated from the 3 MLCT/ 3 LLCT [dπ(Pt)/ π(C≡CR) → π*(terpyridine)] excited state with similar trends to their electronic absorptions.…”

Section: Resultsmentioning

confidence: 92%

Multiaddressable molecular rectangles with reversible host–guest interactions: Modulation of pH-controlled guest release and capture

Chan

Lam

Tanaka

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

118

View full text Add to dashboard Cite

A series of multiaddressable platinum(II) molecular rectangles with different rigidities and cavity sizes has been synthesized by endcapping the U-shaped diplatinum(II) terpyridine moiety with various bisalkynyl ligands. The studies of the host-guest association with various square planar platinum(II), palladium(II), and gold(III) complexes and the related low-dimensional gold(I) complexes, most of which are potential anticancer therapeutics, have been performed. Excellent guest confinement and selectivity of the rectangular architecture have been shown. Introduction of pH-responsive functionalities to the ligand backbone generates multifunctional molecular rectangles that exhibit reversible guest release and capture on the addition of acids and bases, indicating their potential in controlled therapeutics delivery on pH modulation. The reversible host-guest interactions are found to be strongly perturbed by metal-metal and π-π interactions and to a certain extent, electrostatic interactions, giving rise to various spectroscopic changes depending on the nature of the guest molecules. Their binding mode and thermodynamic parameters have been determined by 2D NMR and van't Hoff analysis and supported by computational study. noncovalent interactions | platinum complex | luminescence T he study of metal-metal interactions has drawn enormous attention since the past two decades because of the intriguing spectroscopic and photophysical properties arising from the close proximity of the metal centers (1, 2). Square planar d 8 platinum(II) complexes with coordination unsaturation are one of the important classes of metal complexes that have been extensively explored because of their capability to exhibit metalmetal interactions and display rich photophysical properties (3-26). Platinum(II) terpyridine complexes have been found to exhibit rich polymorphism in the solid state (16)(17)(18)(19)(20) owing to their square planar coordination geometry, which permits facile access to Pt(II)···Pt(II) interactions as well as π-π interactions between the chromophores. It was not until 2001 that the first successful synthesis of platinum(II) terpyridine alkynyl complexes, which possess enhanced solubility and luminescence compared with the chloro counterpart, was reported (16). Additional efforts have been devoted to the use of the system to respond to external stimuli, such as variation in solvent composition (17, 18), pH (19, 20), temperature (21, 22), addition of ionic (24-26), and polymeric species (27,28), in which spectral changes induced by strong Pt(II)···Pt(II) and π−π interactions have been displayed.In the past few decades, enormous efforts have been devoted to the construction of molecular architectures by fusing the organic framework to the transition metal centers through selfassembly processes (29-57). There has been continuous interest in the construction of stimuli-responsive metallosupramolecular architectures with diverse sizes, shapes, and symmetries to rationalize the criteria for molecular recognition and impa...

show abstract

Section: Resultsmentioning

confidence: 92%

Multiaddressable molecular rectangles with reversible host–guest interactions: Modulation of pH-controlled guest release and capture

Chan

Lam

Tanaka

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

118

View full text Add to dashboard Cite

show abstract

“…Thus, we have studied the self-aggregation of 56MESS and [Pt(terpy)Cl] + at varying metal complex/salt concentrations and solution temperatures using pulsed gradient spin-echo (PGSE) NMR diffusion measurements. 16 X-Ray crystal structures have shown that platinum(II)-based DNA intercalators can p-p stack in three different configurations; a head-to-head, 17 head-to-tail 18 or pinwheel configuration, where alternate intercalator molecules are rotated B901 compared to the molecule stacked above it. 2 In any configuration, the resultant macromolecule forms a cylinder or rod-like structure.…”

mentioning

confidence: 99%

Diffusion-based studies on the self-stacking and nanorod formation of platinum(ii) intercalators

et al. 2009

View full text Add to dashboard Cite

Pulsed gradient spin-echo nuclear magnetic resonance diffusion measurements have been used to show that platinum(II)-based intercalating agents self-stack in solution and form nanorods 0.45-3.9 nm in length (at 25 mM); their lengths are dependent on metal complex concentration, salt concentration and solution temperature.The anticancer agent 56MESS [(5,6-dimethyl-1,10-phenanthroline)(1S,2S-diaminocyclohexane)platinum(II)] 2+ , Fig. 1a, is our lead candidate in a family of over 60 platinum(II)-based DNA intercalating complexes. [1][2][3][4] It has demonstrated significant in vitro cytotoxicity in cisplatin sensitive and resistant human cancer cell lines. 5 56MESS is thought to induce cellular apoptosis by intercalating double-stranded DNA, thereby preventing DNA transcription and replication. 1 Drug transport, cellular uptake and intracellular glutathione degradation 6 are also thought to play a significant role in the structure-activity relationship of this family of platinum complexes. 1 A number of new platinum(II)-based DNA intercalator complexes are also being developed that contain terpyridine intercalating groups (e.g. [(2,2 0 :6 0 ,2 00 -terpyridine)chloro-platinum(II)] + [Pt(terpy)Cl] + ; Fig. 1b). 7-9 A number of these compounds display activity similar to, or greater than, cisplatin in several cell lines. 10 It is widely accepted that compounds that contain fused aromatic rings are capable of forming dimers in solution through favourable p-p stacking. 11 Platinum(II) complexes containing planar aromatic ligands have been shown to stack and form dimers in aqueous solvents; however, these investigations have been limited to one-dimensional 1 H nuclear magnetic resonance (NMR) and electronic spectroscopy. [11][12][13][14] The formation of higher order aggregates (i.e. greater than two molecules) of these compounds has not been well demonstrated. The self-assembly of these complexes, particularly under physiological-like conditions, is of great importance, as aggregation may influence the ability of the complex to intercalate with DNA. In addition, the formation of large aggregates may influence the rate of drug transport/uptake. 15 56MESS and [Pt(terpy)Cl] + serve as excellent model compounds for initial investigations of such aggregation mechanisms. Thus, we have studied the self-aggregation of 56MESS and [Pt(terpy)Cl] + at varying metal complex/salt concentrations and solution temperatures using pulsed gradient spin-echo (PGSE) NMR diffusion measurements. 16 X-Ray crystal structures have shown that platinum(II)-based DNA intercalators can p-p stack in three different configurations; a head-to-head, 17 head-to-tail 18 or pinwheel configuration, where alternate intercalator molecules are rotated B901 compared to the molecule stacked above it. 2 In any configuration, the resultant macromolecule forms a cylinder or rod-like structure. We have employed the simple model of an ellipsoid (oblate or prolate, ESIw, Fig. S5) for the determination of macromolecule length. By substituting the observed diffusion coef...

show abstract

“…The structure of the latter has been determined in a single crystal x-ray diffraction study (24). Previous work showed the 300-350 nm spectral region of platinum terpyridine complexes to be sensitive to the nature of the ligand in the fourth coordination site (24). The spectrum of the 1:1 mixture of platinum terpyridine nitrate and UMPS is strongly suggestive of platinumsulfur binding.…”

Section: Resultsmentioning

confidence: 99%

“…2 compares the electronic spectra of platinum terpyridine nitrate before and after the addition-of an equimolar amount of UMPS with that of [(terpy)Pt(HET)]NO3. The structure of the latter has been determined in a single crystal x-ray diffraction study (24). Previous work showed the 300-350 nm spectral region of platinum terpyridine complexes to be sensitive to the nature of the ligand in the fourth coordination site (24).…”

Section: Resultsmentioning

confidence: 99%

Platinum binds selectively to phosphorothioate groups in mono- and polynucleotides: a general method for heavy metal staining of specific nucleotides.

Strothkamp¹,

Lippard²

1976

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Platinum binding to nucleoside phosphorothioates has been examined to determine their suitability as heavy metal labeling sites for the potential electron microscopic sequencing of nucleic acids. The complex platinum terpyridine nitrate forms a 1:1 adduct with either adenosine or uridine monophosphorothioate. Spectroscopic evidence strongly indicates the presence of platinum-sulfur bonds. Both platinum terpyridine nitrate and chloroterpyridineplatinum(II) bind to poly(sA-U), a polymer prepared from adenosine 5'-O-(1-thiotriphosphate) and UTP. Binding to the sulfur atoms of the phosphorothioate groups is quantitative, as shown by double label experiments using [35S]poly(sA-U) and [3H]chloroterpyridine-platinum(II). Similar experiments with [14C]poly(A-U) indicated no platinum binding. No evidence of nicking or loss of sulfur from poly(sA-U) could be detected after platinum binding. The phosphorothioate group is a strong, highly selective binding site for platinum in polynucleotides. Previous studies have demonstrated quantitative enzymatic incorporation of phosphorothioate groups into a polynucleotide adjacent to a specific base [Matzura, H. & Eckstein, F. (1968) Eur. J. Biochem. 3, 448-452]. The use of heavy metal-labeled phosphorothioate groups for the sequencing of nucleic acids by electron microscopy therefore appears feasible.

show abstract

Metallointercalation reagents. Synthesis, characterization, and structural properties of thiolato(2,2',2''-terpyridine)platinum(II) complexes

Abstract: The charge transfer contribution is minimal in the ground state of these complexes. ( 27) The relationship is actually parabolic26 and becomes linear at only small energy differences.(28) For a discussion of bridging groups in inner-sphere electron transfer reactions see A.

Cited by 263 publications

References 9 publications

Multiaddressable molecular rectangles with reversible host–guest interactions: Modulation of pH-controlled guest release and capture

Multiaddressable molecular rectangles with reversible host–guest interactions: Modulation of pH-controlled guest release and capture

Diffusion-based studies on the self-stacking and nanorod formation of platinum(ii) intercalators

Platinum binds selectively to phosphorothioate groups in mono- and polynucleotides: a general method for heavy metal staining of specific nucleotides.

Contact Info

Product

Resources

About