Dominic V. McGrath

Honors

• Camille Dreyfus Teacher Scholar Award, 1999-2004
• Research Corporation Cottrell Scholar, 1997-2002
• NSF CAREER Award, 1997-2002

Education and Appointments

• B.S. 1986, Yale University
  
• Ph.D. 1992, California Institute of Technology
  

Research Interests

• Organic
  
• Materials Synthesis and Characterization
  
• Polymers
  
• Synthesis and Synthetic Methodology
  

Research Summary

Our research program involves the use of organic synthesis for the design, development, and application of new concepts in macromolecular, supramolecular, and materials chemistry. Our research efforts span a number of areas in the chemical sciences and include studies of (a) chiral dendritic macromolecules and the effect of chiral subunits on dendrimer conformation, (b) dendrimers and linear polymers which undergo structural changes in response to visible light and other stimuli, (c) liquid crystalline materials based on dendritic and photochromic mesogens, and (d) the influence of dendritic components of nanoscopic systems on phonic and electronic properties of materials.

We have developed several new classes of dendritic materials containing photochromic subunits. As nature uses light energy to alter function in photoresponsive systems such as photosynthesis, vision, phototropism, and phototaxis, we use light energy to drive gross topological or constitutional changes in fundamentally new dendritic architectures with precisely placed photoresponsive subunits. In short, we can drive dendrimer properties with light stimuli. We have developed two entirely new classes of photoresponsive dendritic macromolecules: (1) Photochromic Dendrimers, and (2) Photolabile Dendrimers. We anticipate that switchable and degradable dendrimers of this type will have application in small molecule transport systems based on their ability to reversibly encapsulate guest molecules. We are continuing to develop these materials as potential transport hosts and photoresponsive supramolecular assemblies.

Our interest in labile macromolecular structures has led to our development of the process of dendrimer disassembly, whereby a triggering stimulus initiates an electronic cascade cleavage of dendritic structures into individual dendrimer subunits or larger dendrimer fragments. This chemistry introduces a new paradigm for the use of dendritic structures based on (1) the nature of dendrimers as covalent assemblages of active species, and using the chemistry of disassembly to release these species into a system; and (2) the role of dendritic components of a system in influencing solubility, energy harvesting, or insulating capabilities, etc., and using the chemistry of disassembly to reverse those contributions to a system. This is a powerful construct, in that dendrimers and dendritic structures can be made up of a wide variety of subunits, compatibilized with many different environments, and incorporated into countless systems. We anticipate that dendritic materials with disassembly capabilities will (a) be useful for traditional polymer degradation technologies, and (b) have potential applications in nanotechnology, biomedicine, sensors, etc.

Reduced aggregation of a quinacridone core in dendrimers of increasing generation enhances solid state luminescence efficiency [Chem. Commun. 2005 444]

Selected Publications

• "Synthesis and Study of Non-Aggregating Octasubstituted Dendritic Phthalocyanines, " Kernag, C.A; McGrath, D.V. Israel J. Chem. 2009 49, 9-21.

• "Asymmetric Phthalocyanine Synthesis by ROMP-Capture-Release." Chen, X.; Salmon III, T. R.; McGrath, D. V. Org. Lett. 2009 11, 2061-2064.

• "Site-isolated, Intermolecularly Photocrosslinkable and Patternable Dendritic Quinacridones," D'Ambruoso, G.D.; Ross, E.E.; Armstrong, N.R.; McGrath, D.V. Chem. Commun. 2009 3222-3224.

• "Synthesis and Degradation of Photolabile Dendrimers Based on o-Nitrobenzyl Ether Photolabile Cores," Kevwitch, R.M.; McGrath, D.V. New J. Chem 2007 31, 1332-1336.

• "EAP hydrogels for pulse-actuated cell system (PACS) architectures." Plata, R. Erik; Rogers, Hallena R.; Banister, Mark; Vohnout, Sonia; McGrath, Dominic V. Proc. SPIE 2007 6524 (Electroactive Polymer Actuators and Devices (EAPAD) 2007), 65241T/1-65241T/8.

• "Dendrimers Based on Thermally Reversible Furan-Maleimide Diels-Alder Adducts," Szalai, M. L.; McGrath, D.V.; Wheeler, D.R.; Zifer, T.; McElhanon, J.R. Macromolecules 2007 40, 818-823.

• "Synthesis and Degradation of Photolabile Dendrimers Based on o-Nitrobenzyl Ether Photolabile Cores," Kevwitch, R.M.; McGrath, D.V. New J. Chem 2007 31, 1332-1336.

• "Langmuir and Grafted Monolayers of Photochromic Amphiphilic Monodendrons of Low Generations," Genson, Kirsten L.; Holzmuller, Jason; Villacencio, Ovette F.; McGrath, Dominic V.; Vaknin, David; Tsukruk, Vladimir V. J. Phys. Chem. B 2005 109, 20393-20402.

• "Dendrimer Disassembly as a New Paradigm for the Application of Dendritic Structures," McGrath, D.V. Molecular Pharmaceutics 2005 2, 253-263.

• "Dendritic incorporation of quinacridone: solubility, electrochemistry, and solid state luminescence," Ortiz, A.; Flora, W.H.; D’Ambruoso, G.D.; Armstrong, N.R.; McGrath, D.V. Chem. Commun. 2005 444-446.

• "Phototriggering of geometric dendrimer disassembly: an improved synthesis of 2,4-bis(hydroxymethyl)phenol based dendrimers," Szalai, M.L.; McGrath, D.V. Tetrahedron 2004 60, 7261-7266.

• "Photoswitchable Flexible and Shape-Persistent Dendrimers. Comparison of the Interplay between a Photochromic Azobenzene Core and Dendrimer Structure," Liao, L.-X.; Stellacci, F.; McGrath, D.V. J. Am. Chem. Soc. 2004 126, 2181-2185.

• "Geometric Disassembly of Dendrimers: Dendritic Amplification," Szalai, M.L.; Kevwitch, R.M.; McGrath, D.V. J. Am. Chem. Soc. 2003 125, 15688-15689.

• "Dendrimer Disassembly by Benzyl Ether Depolymerization," Li, S.; Szalai, M.L.; Kevwitch, R.M.; McGrath, D.V. J. Am. Chem. Soc. 2003 125, 10516-10517.

• "Non-aggregating octasubstituted dendritic phthalocyanines," Kernag, C.A.; McGrath, D.V. Chem. Commum. 2003 1048-1049.

• "Azobenzene-Containing Dendrimers." Villavicencio, O.F.; McGrath, D.V. Advances in Dendritic Macromolecules 2002 5, 1-44.

• "Synthesis of Photolabile Dendrimer Cores," Kevwitch, R.M.; McGrath, D.V. Synthesis 2002 1171-1176.

• "Hydrobenzoin-Based Rigid Chiral Polymer." Bieging, A.R.; Liao, L.-X.; McGrath, D.V. Chirality 2002 14, 258-263.

• "Photochromic Dendrimers Containing Six Azobenzenes." Liao, L.-X.; Junge, D.M.; McGrath, D. V. Macromolecules. 2002 35, 319-322.