Micheal Harmjanz Assistant Professor – Inorganic Chemistry Diploma, University of Oldenburg 1994 Ph.D., University of Oldenburg 1997 email: mharmjan@uno.edu phone: (504) 280-1125 office: CBS 240

Research Interests The primary aim of Dr. Harmjanz's research initiative is to develop novel inorganic polymers and polymeric inorganic-organic hybrid materials. Although far less common than organic polymers, inorganic polymers often exhibit highly interesting properties that are not accessible with traditional macromolecular organic materials. Given the ease with which many of these polymers can be modified, this research is directed toward problems of industrial and biomedical importance. Among the broad library of polymeric scaffolds, functionalized polyphosphazenes offer a unique environment to simultaneously provide receptor targeting vectors and well-defined metal coordination sites. Thus, the successful complexation of technetium or rhenium by these macromolecules will establish a new and highly flexible way to develop in vivo screening methodologies and to provide radio-therapeutic tools with significantly improved biodistribution characteristics. In this interdisciplinary approach we aim to exploit the broad, untapped potential of these macromolecules for the binding of the heavier Group 7 metals. Moreover, utilizing the related low molecular weight cyclotriphosphazene monomers to improve the metal binding characteristics of the polymers, this scheme also provides a straightforward strategy for the binding of other radionuclides and the immobilization of homogeneous catalysts. Further efforts aim towards the generation of macromolecular organic-inorganic hybrid materials based on bisimido type transition metal complexes. This approach offers a number of variables to be incorporated into the high molecular weight materials, including the type of the metal centers, variations of their coordination spheres and substantial changes of the electronic and structural nature of the respective organic bridging unit. As a result, the chemical and physical features of the polymers can easily be tailored to meet specific needs. Another related area of interest focuses on metal loaded amphiphilic inorganic-organic hybrid copolymers. Employing recently developed living polymerization techniques, inorganic segments will be generated that allow for the incorporation of metal binding sites positioned either at the end of the macromolecular chain and/or at the polymeric backbone. As a consequence of the built-in amphiphilicity, these macromolecules will undergo micellization in solvents that preferable dissolve only one segment. The given approach addresses a number of criteria critical for micelle formation such as control over the molecular weight range and monodispersity as well as the solubility of the respective segments. The new materials are highly interesting candidates for the generation of sophisticated micelle based sensors or quasi-biphasic microreactors. Moreover, exciting applications in radiopharmacy and material sciences can be envisioned.

Selected Publications Harmjanz, M.; Saak, W.; Haase, D.; Pohl, S.: “Aryl Isonitrile Binding to [Fe4S4] Clusters: Formation of [Fe4S4]+ and [{Fe4S4}2]2+ cores”, Chem. Commun., 1997, 951. Harmjanz, M.; Scott, M. J.: “A Convenient Synthesis of Porphodimethenes and Their Conversion to Trans-Porphyrins with Two Functionalized Meso-Naphthyl-Substituents”, Chem. Commun., 2000, 397. Harmjanz, M.; Schneider, J.; Saak, W.; Henkel, G.; Pohl, S.: “1,3-Bis(N, N, N', N'-tetramethylguanidino)propane: Synthesis, Characterization and Bonding Properties of the First Bidentate, Peralkylated Guanidine Ligand”, J. Chem. Soc. Dalton Trans., 2000, 19, 3473. Harmjanz, M.; Gill, H. S.; Scott, M. J.: “Porphodimethene-Porphyrin Interconversion: A Tetrapyrrolic Redox-Switchable Macrocycle”, J. Am. Chem. Soc., 2000, 122, 10476. Harmjanz, M.; Scott, M. J.: “Facile Synthesis of Stacked, Heteronuclear Porphyrin Arrays with Varied Architectures”, Inorg. Chem., 2000, 39, 5428. Harmjanz, M.; Gill, H. S.; Scott, M. J.: “New Methodologies for the Preparation of Porphodimethenes and Their Conversion to Trans-Porphyrins with Functionalized Naphthyl Spacers”, J. Organ. Chem., 2001, 66, 5374. Harmjanz, M.; Božidarević, I.; Scott, M. J.: “MacDonald [2+2]-Type Condensation with Vicinal Diketones: Synthesis and Properties of Novel Spiro-Tricyclic Porphodimethenes”, Org. Lett., 2001, 3, 2281. Harmjanz, M.; Scott, B. L.; Burns, C. J.: First Rhenium Complexes Based on Cyclotriphosphazene Scaffolds with Exocyclic Pyrazolyl Substituents”, Chem. Commun., 2002, 1386. Gill, H. S.; Harmjanz, M.; Santamaria, J.; Finger, I.; Scott, M. J.: “Facile Oxidative Rearrangement of Dispiro-Porphodimethenes to Unprecedented Non-Planar and Sheet-like Porphyrins with Intense Absorptions in the Near IR Region“, Angewandte Chemie, 2004, 43, 485. Harmjanz, M.; Pieglosiewicz I. M.; Scott, B. L.; Burns, C. J.: “Generation of Spiro-Tricyclic Site-Differentiated Cyclotriphosphazenes: A Solvent-Free Approach to Multidentate N/O-Donor Ligand Systems”, Inorg. Chem., 2004, 43, 642.