School of Chemical Sciences
Prof Penny Brothers
Job title: Professor
Qualifications and associations: BSc, MSc, PhD
|Current projects include the following:
Porphyrin complexes: designing new chemical bonds, sugar sensors, and anticancer agents.Metalloporphyrin complexes occur naturally in hemoglobin, myoglobin and cytochromes. Synthetic porphyrin complexes are used widely as catalysts, in new materials, and as potential therapeutic agents. These applications are possible because the porphyrin ligand imparts interesting and unusual properties to the chemistry of the central atom. An important recent area of chemistry concerns compounds containing bonds between transition metals and the heavier main group elements. One reason for this interest is the quest to understand the extent and nature of transition metal - main group element multiple bonds. This chemistry can be approached by using the porphyrin ligand to define the coordination sphere of either the main group or the transition metal fragment. This project involves the synthesis and characterisation of new main group porphyrin complexes, and of heterobimetallic porphyrin complexes containing both transition metal and main group elements.
Our research group is the first in the world to prepare complexes containing boron coordinated to the porphyrin ligand. They are very unusual in that they contain two boron atoms coordinated in the porphyrin cavity, in contrast to almost every other porphyrin complex which contains only one coordinated atom. The resulting compounds could be useful in two areas, as sugar sensors, in which sugar molecules form covalent links to boronic acid groups, and in Boron Neutron Capture Therapy. BNCT utilizes the capture of slow thermal neutrons by 10B atoms located in the vicinity of tumour cells. Porphyrins are known to localize on the surface of solid tumours, and so a porphyrin or related expanded porphyrin containing coordinated boron atoms would be a useful target for BNCT. This project involves both fundamental studies directed at learning more about boron poprhyrin complexes, and also specific experiments designed to test their feasibility for use as sugar sensors or BNCT anticancer agents.
The chemistry of new materials for a sustainable futureAdvances in chemistry are essential to the design and synthesis of new materials and the development of new practices that will enable our current civilization to become sustainable. The concepts of Green Chemistry provide important guiding principles in this endeavor. Three research projects are offered under this umbrella. The first is concerned with solar energy conversion, and will involve the design and construction of supramolecular assemblies of photoactive molecules. The second project will be concerned with the utilization of atmospheric CO2 as a renewable chemical feedstock. Carbon dioxide is one of the major greenhouse gases, and an important frontier in current research is the search for methods not only to reduce or eliminate net CO2 emissions, but also to convert CO2 into useful chemicals. The approach taken here will involve synthesis of metal complexes designed to chemically activate CO2 and its subsequent conversion to useful molecules. The aim of the third project is to design and synthesis a metal complex which can act as an electrode catalyst for the reduction of oxygen in a fuel cell. A fuel cell is an electrochemical cell which derives energy from the reduction of O2 and the oxidation of H2, both of which give water as the product. A catalyst is required for the oxygen reduction process in order for the fuel cell to operate at maximum efficiency.These projects will be co-supervised by Assoc Prof Peter Boyd, Assoc Prof Penny Brothers, and Assoc Prof James Wright.
Metal complexes as potential imaging agents and anti-cancer drugsInorganic medicinal chemistry is a rapidly developing field, spurred largely by the tremendous success of the Pt-based anti-cancer drugs like Cisplatin. The unique complexing and redox properties of metal centres can be exploited in the rational design and synthesis of new metal-based anti-cancer drugs. Hypoxia-selective and radiation activated anti-cancer drugs, in which the drug is activated either in the oxygen-deficient, chemically reducing environment of solid tumour cells, or during radiation therapy, are a particular target in this project. The synthesis and chemistry of new complexes of cobalt, chromium or ruthenium, containing small bioactive organic groups as ligands, will be explored. This project is in collaboration with Dr David Ware of the Auckland Cancer Research Centre (Faculty of Medicine), and new complexes will be screened for anti-cancer activity.
Metal complexes containing encapsulating ligands are becoming increasingly important in medical imaging and therapeutic applications. Recent work from our group on the reactions of ligands coordinated to cobalt has led to the development of synthetic routes to new polydentate ligands which encapsulate the metal ion. This project will explore the extension of this chemistry to main group metals such as bismuth and antimony, in order to prepare kinetically inert complexes of these usually labile elements. The project is in collaboration with Dr David Ware.
| Buckley, HL (Buckley, Heather L.); Chomitz, WA (Chomitz, Wayne A.); Koszarna, B (Koszarna, Beata) ; Tasior, M (Tasior, Mariusz) ; Gryko, DT (Gryko, Daniel T.) ; Brothers, PJ (Brothers, Penelope J.) ; Arnold, J (Arnold, John). Synthesis of lithium corrole and its use as a reagent for the preparation of cyclopentadienyl zirconium and titanium corrole complexes . CHEMICAL COMMUNICATIONS Volume: 48 Issue: 87 Pages: 10766-10768 DOI: 10.1039/c2cc35984g Published: 2012 . 2012.
Chang, JYC (Chang, John Yu-Chih) ; Stevenson, RJ (Stevenson, Ralph J.); Lu, GL (Lu, Guo-Liang ; Brothers, PJ (Brothers, Penelope J.); Clark, GR (Clark, George R.); Denny, WA (Denny, William A.)[ 2 ] ; Ware, DC (Ware, David C.). Syntheses of 8-quinolinolatocobalt(III) complexes containing cyclen based auxiliary ligands as models for hypoxia-activated prodrugs . DALTON TRANSACTIONS Volume: 39 Issue: 48 Pages: 11535-11550 DOI: 10.1039/c0dt01142h Published: 2010 . 2012.
Brothers, PJ (Brothers, Penelope J.) . Boron Complexes of Pyrrolyl Ligands . INORGANIC CHEMISTRY Volume: 50 Issue: 24 Pages: 12374-12386 DOI: 10.1021/ic2011919 Published: DEC 19 2011 . 2011.
Lemon, CM (Lemon, Christopher M.) ; Brothers, PJ (Brothers, Penelope J.). The synthesis, reactivity, and peripheral functionalization of corroles . JOURNAL OF PORPHYRINS AND PHTHALOCYANINES Volume: 15 Issue: 9-10 Pages: 809-834 DOI: 10.1142/S1088424611003896 Published: SEP-OCT 2011 . 2011.
Lu, GL (Lu, Guo-Liang ; Stevenson, RJ (Stevenson, Ralph J.) ; Chang, JYC (Chang, John Yu-Chih); Brothers, PJ (Brothers, Penelope J.); Ware, DC (Ware, David C.); Wilson, WR (Wilson, William R.) ; Denny, WA (Denny, William A.) ; Tercel, M (Tercel, Moana) . N-alkylated cyclen cobalt(III) complexes of 1-(chloromethyl)-3-(5,6,7-trimethoxyindol-2-ylcarbonyl)-2,3-dihydro-1H-pyrrolo[3,2-f]quinolin-5-ol DNA alkylating agent as hypoxia-activated prodrugs . BIOORGANIC & MEDICINAL CHEMISTRY Volume: 19 Issue: 16 Pages: 4861-4867 DOI: 10.1016/j.bmc.2011.06.076 Published: AUG 15 2011 . 2011.
Fang, HY (Fang, Huayi) ; Ling, Z (Ling, Zhen) ; Brothers, PJ (Brothers, Penelope J.) ; Fu, XF (Fu, Xuefeng. Reactivity studies of a corrole germanium hydride complex with aldehydes, olefins and alkyl halides . CHEMICAL COMMUNICATIONS Volume: 47 Issue: 42 Pages: 11677-11679 DOI: 10.1039/c1cc15076f Published: 2011 . 2011.
Lemon, CM (Lemon, Christopher M.); Brothers, PJ (Brothers, Penelope J.); Boitrel, B (Boitrel, Bernard). Porphyrin complexes of the period 6 main group and late transition metals . DALTON TRANSACTIONS Volume: 40 Issue: 25 Pages: 6591-6609 DOI: 10.1039/c0dt01711f Published: 2011 . 2011.
Gonzalez, E (Gonzalez, Emmanuel) ; Brothers, PJ (Brothers, Penelope J.) ; Ghosh, A (Ghosh, Abhik). Density Functional Theory Calculations on Ruthenium(IV) Bis(amido) Porphyrins: Search for a Broader Perspective of Heme Protein Compound II Intermediates . JOURNAL OF PHYSICAL CHEMISTRY B Volume: 114 Issue: 46 Pages: 15380-15388 DOI: 10.1021/jp107692m Published: NOV 25 2010 . 2010.
Albrett A.M.,Boyd P.D.W., Clark G.R., Gonzalez E., Ghosh A., Brothers P.J.. Reductive coupling and protonation leading to diboron corroles with a B-H-B bridge . DALTON TRANSACTIONS Volume: 39 Issue: 17 Pages: 4032-4034 Published: 2010 . 2010. Abstract
Albrett, A.M.; Conradie, J.; Ghosh, A.; Brothers, P. J.. DFT survey of monoboron and diboron corroles: regio- and stereochemical preferences for a constrained, low-symmetry macrocycle.. Dalton Trans. 2008, 4464 - 4473. 2008.