Current Projects

Late transition metals form polarized single and multiple bonds with main-group elements (e.g., Si) that exhibit reactivity quite distinct from the ubiquitous metal–carbon bonds.  In this project, we constrain the relevant M–E bond using a pincer ligand in order to examine and exploit the resulting unusual reactivity.  We have examined transformations of a variety of substrates with this strategy, including alkenes, alkynes, heteroallenes (especially CO2).  Current efforts are focused on extending lessons from rare metals (ruthenium, rhodium) to abundant ones (iron, cobalt, nickel) and delineating a set of principles that enables cooperative catalysis at M–Si (and other M–E) bonds.

Beilstein J. Org. Chem. 2012, 1554–1563.
Organometallics 2014, 5070–5073.
Dalton Trans. 2016, 9758–9761.
Dalton Trans. 2017, 14757–14761.
Organometallics 2018, 3956–3962.
Organometallics 201938, 1493–1501.
Organometallics 201938, 4420–4432.
+ Comm. Inorg. Chem. 2020, 40, 217–276.
Funding: ACS-PRF (2011–2014), NSF-CAREER (2016–2021), Dreyfus (2016–2021)
Crystal Structure and NMR Data Gallery

This project extends ideas about organosilicon protecting groups from organic chemistry to organometallic systems.  We are exploring whether organosilicon “protecting groups” can be removed to reveal a reactive inorganic group (late-metal imide or nitride).  The principle has been utilized to demonstrate a variety of deoxygenation and desulfurization reactions (including of notoriously difficult and environmentally relevant substrates like carbon monoxide and carbon dioxide).  Current efforts are aimed at electrochemical approaches to silyl-group removal from silylamides at abundant metals, potentially allowing silylamides to serve as nitrene sources in electrocatalytic aziridination and related reactions.

Organometallics 2014, 1416–1422.
Inorg. Chem. 2015, 3670–3679.
Funding: Research Corporation (2011–2014), ACS-PRF (2015–2018), Dreyfus (2016–2021)
Crystal Structure and NMR Data Gallery

This project is carried out as part of CHEM 352: Advanced Laboratory in Inorganic Chemistry.  Students make a number of new complexes during the term, including a series of piano-stool Mo(II) complexes featuring acyl ligands formed by CO insertion.  Student groups have crystallized a number of these featuring different phosphine co-ligands and collected structural data in a collaboration with Prof. Daron Janzen at St. Catherine University, revealing some interesting trends related to phosphine substituents, and we have published a number of these structures.

Acta Crystallogr., Sect. E: Struct. Rep. Online 2012, m1158–m1159.
Acta Crystallogr., Sect. E: Struct. Rep. Online 2013, m475–m476.
J. Chem. Educ. 2014, 1050–1053.
Acta Crystallogr., Sect. E: Struct. Rep. Online 2014, 216–220.
IUCrData 20172, x170042.
+ Acta Crystallogr., Sect. E: Crystallogr. Commun. 2020, 76, 547–551.
Funding: HHMI (2012–2014), Dreyfus (2016–2021)
Crystal Structure Gallery