A.B. Western Reserve University (1961) Ph.D. University of Illinois (1964)

Inorganic Chemistry

A unifying theme of my research program is to utilize metallo-radical and organo-metal substrate reactions to obtain both energy relevant small molecule organometallic transformations and living radical polymerization for applications in block copolymer materials. These two current focal areas of research are briefly described below. A broad based program in polymer chemistry sponsored by NSF spans areas from transition metal catalyst development and block copolymer synthesis to technological applications of self assembled nano-structured polymer arrays. Reactivity of metal-centered radical species and organometallic derivatives are used in the control of radical polymerization through both catalytic chain transfer and living radical polymerization. Organo-cobalt porphyrin complexes mediate a highly precise living radical polymerization of vinyl monomers such as acrylates and vinyl esters to form low polydispersity homopolymers and block co-polymer materials. This pathway to obtain living radical polymerization is a transition metal form of degenerative transfer that we refer to as radical interchange polymerization (RIP). Living radical polymerization provides access to a vast array of new classes of block copolymers. Self assembly of amphiphilic block copolymers into micelles and nano-structured arrays have many technological applications in nano-reactors, gene and drug delivery, dispersants, metal nanoparticle synthesis, water and fuel cell membranes, sensors, and solar cells which are being developed through collaborations with materials scientists and engineers. New materials design strategies are determined for each of the central topics along with the requisite approaches for polymer synthesis, morphology, and property evaluation. Our energy related catalysis research supported by DOE is focused on developing new strategies to accomplish thermodynamically and kinetically challenging substrate reactions such as methane activation and carbon monoxide reductive coupling. Ligands are designed to achieve high selectivity through steric and electronic constraints on forming the transition states for substrate reactions. The primary focus is on group nine (Co, Rh, Ir) metal complexes where the importance of metallo-radicals is a recurring theme. Metallo-porphyrins, chlorophylls, and related macrocyclic complexes are prominent thermal and photocatalysts in biological systems and emerging as important catalyst materials for chemical manufacturing processes. The unique chemical and physical properties of metallo-porphyrins and macrocyclic complexes are used in producing thermal and photocatalytic cycles for small molecule reactions.Several important examples include hydrogenation of CO and CO2, activation of methane, oxidation of alkenes, photoreductions, and alkene polymerization. Tethered diporphyrin ligands have been designed and synthesized that are used in forming bimetalloradical complexes of Rh(II). Bimetalloradicals provide preorganization of transition states that involve two metalloradicals and give rapid highly selective substrate reactions. Structural, kinetic-mechanistic, thermodynamic, and reactivity studies are used in characterizing intermediates, anticipating new types of reactions, and guiding the design of strategies to produce selective catalyst materials.

Imler, Gregory H.; Peters, Garvin M.; Zdilla, Michael J.; Wayland Bradford B. "Heterobimetallic Complexes of Rhodium Dibenzotetramethylaza[14]annulene [(tmtaa)Rh-M]: Formation Structures, and Bond Dissociation Energetics" Inorganic Chemistry, (2015), 54, 273-279.

Odhner, Johanan H.; Tibbetts, Katharine Moore; Tangeysh, Behzad; et al. "Mechanism of Improved Au Nanoparticle Size Distributions Using Simultaneous Spatial and Temporal Focusing for Femtosecond Laser Irradiation of Aqueous KAuCl4" Journal of Physical Chemistry, (2014), 118, 41, 23986-23995.

Imler, Gregory H.; Zdilla, Michael J.; Wayland, Bradford B. "Equilibrium Thermodynamics To Form a Rhodium Formyl Complex from Reactions of CO and H-2: Metal sigma Donor Activation of CO" Journal of the American Chemical Society, (2014), 136, 16, 5856-5859.

Zhu, Xiaobo; Fryd, Michael; Wayland, Bradford B. "Effects of placing negatively charged groups at the corona terminus on the aqueous dispersion stabilities for PCL-b-PEO block copolymer micelles" POLYMER, (2014), 55, 6, 1467-1473.

Zhu, Xiaobo; Fryd, Michael; Valentine, Ann M.; et al. "Corona charge selective micellle degradation catalyzed by P. cepacia lipase isoforms" CHEMICAL COMMUNICATIONS, (2014), 50, 8, 964-967.

Imler, Gregory H.; Zdilla, Michael J.; Wayland Bradford B. "Evaluation of the Rh-(II)-Rh-(II) Bond Dissociation Enthalpy for [(TMTAA)Rh](2) by H-1 NMR T-2 Measurements: Application in Determining the Rh-C(O)-BDE in [(TMTAA)Rh](2)C=O" INORGANIC CHEMISTRY, (2013), 52, 19, 11509-11513.

Tangeysh, Behzad; Tibbetts, Katherine Moore; Odhner, Johanan H.; et al. "Gold Nanoparticle Synthesis Using Spatially and Temporally Shaped Femtosecond Laser Pulses: Post-Irradiation Auto-Reduction of Aqueous [AuCl4](-)" Journal of Physical Chemistry C, (2013), 117, 36, 18719-18727.

Zhu, Xiaobo; Fryd, Michael; Wayland, Bradford B. "Kinetic-mechanistic studies of lipase-polymer micelle binding and catalytic degradation: Enzyme interfacial activation" POLYMER DEGRADATION AND STABILITY, (2013), 98, 6, 1173-1181.

Zhu, Xiaobo; Sharma Vishnu D.; Fryd, Michael; et al. "Enzyme and acid catalyzed degradation of PEG(45)-b-PBO0,6,9-b-PCL60 micelles: Increased hydrolytic stability by engineering the hydrophilic-hydrphobic interface" POLYMER, (2013), 54, 12, 2879-2886.

Bhagan, Salome; Imler, Gregory H.; Wayland, Bradford B. "Iridium Porphyris in CD3OD: Reduction of Ir(III), CD3-OD Bond Cleavage, Ir-D Acid Dissociation and Alkene Reactions" INORGANIC CHEMISTRY, (2013), 52, 8, 4611-4617.

Ye, Zichuan; Wayland, Bradford B. "Mechanistic Aspects of Living Radical Polymerization Mediated by Organometallic Complexes" BS FUNDAMENTALS OF CONTROLLED/LIVING RADICAL POLYMERIZATION, (2013), 4, 168-204.

Ye, Zichuan; Tangeysh, Behzad; Wayland, Bradford B. "Metal dication cross-linked polymer network colloids as an approach to form and stabilize unusually small metal nanoparticles" CHEMICAL COMMUNICATIONS, (2013), 49, 47, 5372-5374.

Liao, Chei-Ming; Hsu, Ching-Chun; Wang, Fu-Sheng; et al. "Living radical polymerization of vinyl acetate and methyl acrylate mediated by Co(Salen*) complexes" POLYMER CHEMISTRY, (2013), 4, 10, 3098-3014.

Imler, Gregory H.; Lu, Zhi; Kistler, Kurt A.; et al. "Complexes of 2,5-Bis(alpha-pyridyl)pyrrolate with Pd(III) and Pt(II): A Monoanionic Iso-pi-Electron Ligand Analog of Terpyridine" INORGANIC CHEMISTRY, (2012), 51, 19, 10122-10128.