Dominic V Mcgrath

Professor, Chemistry and Biochemistry-Sci

Professor, BIO5 Institute

Primary Department

Chemistry & Biochemistry

Department Affiliations

Chemistry & Biochemistry

BIO5 Institute

Contact

(520) 626-4690

mcgrath@u.arizona.edu

Research Interest

Dominic Mcgrath, PhD, set forth a program which involves the use of organic synthesis for the design, development, and application of new concepts in macromolecular, supramolecular, and materials chemistry. Research efforts span a number of areas in the chemical sciences and include studies of: 1) chiral dendritic macromolecules and the effect of chiral subunits on dendrimer conformation, 2) photochromic dendrimers and linear polymers which undergo structural changes in response to visible light, 3) liquid crystalline materials based on dendritic and photochromic mesogens, and 4) synthesis of new ligands based on saturated nitrogen heterocycles.A continuing interest remains in the effect of structural perturbations on the properties and functional of dendritic macromolecules. Part of this research addresses the design, synthesis, and study of dendrimeric materials containing chiral moieties in the interior for influencing the conformational order of these 3-dimensional macromolecules. An ultimate goal is to develop materials active for the selective clathration of small guest molecules. Potential applications include chemical separations, sensor technology, environmental remediation, and asymmetric catalysis.Dr. Mcgrath and his lab team recently 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, they use light energy to drive gross topological or constitutional changes in fundamentally new dendritic architectures with precisely placed photoresponsive subunits. In short, they can drive dendrimer properties with light stimuli. Two entirely new classes of photoresponsive dendritic macromolecules have been developed and include: 1) photochromic dendrimers and 2) photolabile dendrimers. Dr. Mcgrath anticipates 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. He continues to develop these materials as potential transport hosts and photoresponsive supramolecular assemblies.

Publications

Phototriggering of geometric dendrimer disassembly: An improved synthesis of 2,4-bis(hydroxymethyl)phenol based dendrimers

Szalai, M. L., & McGrath, D. V. (2004). Phototriggering of geometric dendrimer disassembly: An improved synthesis of 2,4-bis(hydroxymethyl)phenol based dendrimers. Tetrahedron, 60(34), 7261-7266. doi:10.1016/j.tet.2004.06.078

Abstract:

Dendrimers capable of phototriggered disassembly were prepared up to the second-generation using an improved synthesis of 2,4-bis(hydroxymethyl)phenol based dendrimers. It was found that disassembly proceeds to 75-80% completion after 2 h of irradiation at 310 nm for all molecules studied. The lack of complete reaction is attributed to an inefficient photochemical deprotection process rather than the disassembly itself. © 2004 Elsevier Ltd. All rights reserved.

Constitution, configuration, and the optical activity of chiral dendrimers

McElhanon, J. R., & McGrath, D. V. (1997). Constitution, configuration, and the optical activity of chiral dendrimers. American Chemical Society, Polymer Preprints, Division of Polymer Chemistry, 38(1), 278-279.

An efficient reverse Diels-Alder approach for the synthesis of N-alkyl bismaleimides

Rao, V., Navath, S., Kottur, M., McElhanon, J. R., & McGrath, D. V. (2013). An efficient reverse Diels-Alder approach for the synthesis of N-alkyl bismaleimides. Tetrahedron Letters, 54(37), 5011-5013. doi:http://dx.doi.org/10.1016/j.tetlet.2013.07.002

Abstract:

Bismaleimides are useful precursors for Diels-Alder reactions, Michael additions, and thiol-maleimide based conjugation for the synthesis of materials and polymers. Use of bismaleimide cross linkers for generating polymers, bioconjugate molecules, and useful imaging molecules is an active area of research. An efficient and practical synthetic protocol for N-alkyl bis-maleimide cross linkers starting from furan protected maleimide employing a reverse Diels-Alder reaction is reported. © 2013 Elsevier Ltd. All rights reserved.

Macromolecular isomers of azobenzene-containing photochromic dendrimers

Sheng, L. i., & McGrath, D. V. (2000). Macromolecular isomers of azobenzene-containing photochromic dendrimers. American Chemical Society, Polymer Preprints, Division of Polymer Chemistry, 41(1), 861-862.

Abstract:

Second generation dendrimer 2 with single azobenzene moieties attached to the periphery of each dendron is prepared by using protection-deprotection methodology. This modified convergent method using key intermediates methyl 3-benzyloxy-5-hydroxybenzoate (4) and methyl 3-allyloxy-5-hydroxybenzoate (8) is used widely in precise dendrimer synthesis. Preparation of higher generation of dendrimers with only one azobenzene moiety in the exterior of each dendron is ongoing. The complete comparison of physical properties between the two types of dendrimers 1 and 2 is investigated.

Langmuir-Blodgett monolayers from lower generation amphiphilic monodendrons

Peleshanko, S., Sidorenko, A., Larson, K., Villavicencio, O., Ornatska, M., McGrath, D. V., & Tsukruk, V. V. (2002). Langmuir-Blodgett monolayers from lower generation amphiphilic monodendrons. Thin Solid Films, 406(1-2), 233-240.

Abstract:

Amphiphilic monodendrons of lower generations, AD12-N, containing a benzyl-15-crown-5 polar focal point, photochromic spacer and different number of dodecyl tails as peripheral groups (n = 1-8) have been investigated for their ability to form uniform monolayers at solid surfaces. The surface pressure-area behavior, photomechanical behavior and the morphology of the monomolecular films were investigated. We observed that all compounds studied are capable of forming stable Langmuir and Langmuir Blodgett monolayers, with virtually flat packing of molecules. Higher generation dendrimers form very uniform monolayers, without the usual domain microstructure. For AD12-4 monolayer on solid support, we observed stripped microstructure with several layers (3-6) bundled together. The periodicity of this structure of 8 nm was close to layered spacing, obtained from X-ray data for bulk material. For this compound, we proposed the model of double-layered packing of the molecules, with partial overlapping of the central segments and suggested that deposition on a solid substrate resulted in changing orientation of molecular fragments. Fast reversible photochromic response was observed for all monolayers with a conversion level of 50%. © 2002 Elsevier Science B.V. All rights reserved.

Dominic V Mcgrath