New Platinum(II) and Rhenium(I) Complexes of "Linear" Chelate Ligands Terminated with Pyridyl or Imidazolyl N-Donor Groups

Author

Himali Kokila Ranasinghe Pilana Vithanage, Louisiana State University and Agricultural and Mechanical CollegeFollow

Degree

Doctor of Philosophy (PhD)

Department

Chemistry

Document Type

Dissertation

Abstract

The overall goal of this dissertation research is to design, synthesize, and study new Pt(II) and Re(I) complexes relevant to biomedical applications. One of the projects involves the assessment of the interactions of bulky tridentate carrier ligands with a bound guanine nucleobase derivative (G) in platinum complexes, with a goal of developing chemistry potentially relevant to active anti-cancer Pt drugs. In another project, the fac-[Re^I(CO)₃]⁺ core is used to prepare novel Re(I) complexes with the purpose of developing new linking chemistry relevant to ^99mTc and ¹⁸⁷Re radiopharmaceuticals. This research explores the use of three different types of linear carrier-ligands in approaches directed toward achieving the stated goals.

The first type of linear tridentate carrier ligand employed (N(R)1,1′-Me₂dma, when R = H, bis(1-methyl-2-methylimidazolyl)amine) is terminated by imidazolyl rings and has a central N-donor with an NH or an N−C bond. High in-plane steric bulk in monofunctional Pt(II) complexes is a feature associated with increased anti-cancer activity. Therefore, understanding carrier-ligand steric effects is crucial in designing new platinum drugs. For that purpose, the new N(R)1,1′-Me₂dma ligands were utilized to synthesize [Pt(II)(N(R)1,1′-Me₂dma)Cl]Cl complexes. The chemical behavior of adducts of simple purine derivatives (G) made with these monofunctional Pt(II) complexes was studied. The ligands and complexes were characterized using NMR spectroscopy, single-crystal X-ray crystallography and ESI mass spectrometry. Solution NMR spectroscopy was used as the primary tool to study the Pt(II)(N(R)1,1′-Me₂dma)G adducts. During this work, the 3′-GMP mono adduct of [Pt(N(H)1,1′-Me₂dma)Cl]Cl complex was crystallized, allowing the first crystallographic molecular structure determination for a 3′-GMP platinum(II) complex.

The other two types of linear tridentate ligands have the central N donor in a sulfonamide linkage. New ligands terminated with either two pyridyl rings (second type, N(SO₂R)3,3′,5,5′-Me₄dpa and N(SO₂R)6,6′-Me₂dpa, derivatives of 2-dipicolylamine) or with two imidazolyl rings (third type, N(SO₂R)1,1′-Me₂dma) were prepared. Pt(II) and Re(I) complexes of these new ligands were synthesized and their chemical properties studied.

Date

6-22-2018

Recommended Citation

Pilana Vithanage, Himali Kokila Ranasinghe, "New Platinum(II) and Rhenium(I) Complexes of "Linear" Chelate Ligands Terminated with Pyridyl or Imidazolyl N-Donor Groups" (2018). LSU Doctoral Dissertations. 4641.
https://repository.lsu.edu/gradschool_dissertations/4641

Committee Chair

Marzilli, Luigi

DOI

10.31390/gradschool_dissertations.4641