Christopher J. Cramer
University of Minnesota-Twin Cities
H-index: 115
North America-United States
Description
Christopher J. Cramer, With an exceptional h-index of 115 and a recent h-index of 70 (since 2020), a distinguished researcher at University of Minnesota-Twin Cities, specializes in the field of Chemistry, Catalysis, Theoretical Chemistry, Physical Chemistry.
His recent articles reflect a diverse array of research interests and contributions to the field:
Mechanistic insights into radical formation and functionalization in copper/N-fluorobenzenesulfonimide radical-relay reactions
Radical ring-opening polymerization of sustainably-derived thionoisochromanone
Understanding Antiferromagnetic and Ligand Field Effects on Spin Crossover in a Triple-Decker Dimeric Cr (II) Complex
Correction: Radical ring-opening polymerization of sustainably-derived thionoisochromanone
Metal–Carbodithioate-Based 3D Semiconducting Metal–Organic Framework: Porous Optoelectronic Material for Energy Conversion
Superradiance and Directional Exciton Migration in Metal–Organic Frameworks
Factors affecting the mechanism of 1, 3-butadiene polymerization at open metal sites in Co-MFU-4l
Localized Active Space-State Interaction: a Multireference Method for Chemical Insight
Professor Information
University | University of Minnesota-Twin Cities |
---|---|
Position | ___ |
Citations(all) | 79959 |
Citations(since 2020) | 31955 |
Cited By | 61386 |
hIndex(all) | 115 |
hIndex(since 2020) | 70 |
i10Index(all) | 499 |
i10Index(since 2020) | 306 |
University Profile Page | University of Minnesota-Twin Cities |
Research & Interests List
Chemistry
Catalysis
Theoretical Chemistry
Physical Chemistry
Top articles of Christopher J. Cramer
Mechanistic insights into radical formation and functionalization in copper/N-fluorobenzenesulfonimide radical-relay reactions
Copper-catalysed radical-relay reactions that employ N-fluorobenzenesulfonimide (NFSI) as the oxidant have emerged as highly effective methods for C(sp3)–H functionalization. Herein, computational studies are paired with experimental data to investigate a series of key mechanistic features of these reactions, with a focus on issues related to site-selectivity, enantioselectivity, and C–H substrate scope. (1) The full reaction energetics of enantioselective benzylic C–H cyanation are probed, and an adduct between Cu and the N-sulfonimidyl radical (˙NSI) is implicated as the species that promotes hydrogen-atom transfer (HAT) from the C–H substrate. (2) Benzylic versus 3° C–H site-selectivity is compared with different HAT reagents: Cu/˙NSI, ˙OtBu, and Cl˙, and the data provide insights into the high selectivity for benzylic C–H bonds in Cu/NFSI-catalyzed C–H functionalization reactions. (3) The energetics of three …
Authors
Mukunda Mandal,Joshua A Buss,Si-Jie Chen,Christopher J Cramer,Shannon S Stahl
Journal
Chemical Science
Published Date
2024
Radical ring-opening polymerization of sustainably-derived thionoisochromanone
We present the synthesis, characterization and radical ring-opening polymerization (rROP) capabilities of thionoisochromanone (TIC), a fungi-derivable thionolactone. TIC is the first reported six-membered thionolactone to readily homopolymerize under free radical conditions without the presence of a dormant comonomer or repeated initiation. Even more, the resulting polymer is fully degradable under mild, basic conditions. Computations providing molecular-level insights into the mechanistic and energetic details of polymerization identified a unique S,S,O-orthoester intermediate that leads to a sustained chain-end. This sustained chain-end allowed for the synthesis of a block copolymer of TIC and styrene under entirely free radical conditions without explicit radical control methods such as reversible addition–fragmentation chain transfer polymerization (RAFT). We also report the statistical copolymerization of …
Authors
Emily A Prebihalo,Anna M Luke,Yernaidu Reddi,Christopher J LaSalle,Vijay M Shah,Christopher J Cramer,Theresa M Reineke
Journal
Chemical Science
Published Date
2023
Understanding Antiferromagnetic and Ligand Field Effects on Spin Crossover in a Triple-Decker Dimeric Cr (II) Complex
Two possible explanations for the temperature dependence of spin-crossover (SCO) behavior in the dimeric triple-decker Cr(II) complex ([(η5-C5Me5)Cr(μ2:η5-P5)Cr(η5-C5Me5)]+) have been offered. One invokes variations in antiferromagnetic interactions between the two Cr(II) ions, whereas the other posits the development of a strong ligand-field effect favoring the low-spin ground state. We perform multireference electronic structure calculations based on the multiconfiguration pair-density functional theory to resolve these effects. We find quintet, triplet, and singlet electronic ground states, respectively, for the experimental geometries at high, intermediate, and low temperatures. The ground-state transition from quintet to triplet at an intermediate temperature derives from increased antiferromagnetic interactions between the two Cr(II) ions. By contrast, the ground-state transition from triplet to singlet at low …
Authors
Arup Sarkar,Matthew R Hermes,Christopher J Cramer,John S Anderson,Laura Gagliardi
Journal
Journal of the American Chemical Society
Published Date
2023/10/3
Correction: Radical ring-opening polymerization of sustainably-derived thionoisochromanone
Correction for ‘Radical ring-opening polymerization of sustainably-derived thionoisochromanone’ by Emily A. Prebihalo et al., Chem. Sci., 2023, https://doi.org/10.1039/d2sc06040j.
Authors
Emily A Prebihalo,Anna M Luke,Yernaidu Reddi,Christopher J LaSalle,Vijay M Shah,Christopher J Cramer,Theresa M Reineke
Journal
Chemical Science
Published Date
2023/6/21
Metal–Carbodithioate-Based 3D Semiconducting Metal–Organic Framework: Porous Optoelectronic Material for Energy Conversion
Solar energy conversion requires the working compositions to generate photoinduced charges with high potential and the ability to deliver charges to the catalytic sites and/or external electrode. These two properties are typically at odds with each other and call for new molecular materials with sufficient conjugation to improve charge conductivity but not as much conjugation as to overly compromise the optical band gap. In this work, we developed a semiconducting metal–organic framework (MOF) prepared explicitly through metal–carbodithioate “(−CS2)nM” linkage chemistry, entailing augmented metal–linker electronic communication. The stronger ligand field and higher covalent character of metal–carbodithioate linkages─when combined with spirofluorene-derived organic struts and nickel(II) ion-based nodes─provided a stable, semiconducting 3D-porous MOF, Spiro-CS2Ni. This MOF lacks long-range …
Authors
Xinlin Li,Ryther Anderson,H Christopher Fry,Saied Md Pratik,Wenqian Xu,Subhadip Goswami,Taylor G Allen,Jierui Yu,Sreehari Surendran Rajasree,Christopher J Cramer,Garry Rumbles,Diego A Gómez-Gualdrón,Pravas Deria
Journal
ACS Applied Materials & Interfaces
Published Date
2023/5/31
Superradiance and Directional Exciton Migration in Metal–Organic Frameworks
Crystalline metal–organic frameworks (MOFs) are promising synthetic analogues of photosynthetic light-harvesting complexes (LHCs). The precise assembly of linkers (organic chromophores) around the topology-defined pores offers the evolution of unique photophysical behaviors that are reminiscence of LHCs. These include MOF excited states with photoabsorbed energy that is spatially dispersed over multiple linkers defining the molecular excitons. The multilinker molecular excitons display superradiance─a hallmark of coupled oscillators seen in LHCs─with radiative rate constant (krad) exceeding that of a single linker. Our theoretical model and experimental results on three zirconium MOFs, namely, PCN-222(Zn), NU-1000, and SIU-100, with similar topology but varying linkers suggest that the size of such molecular excitons depends on the electronic symmetry of the linker. This multilinker exciton model …
Authors
Sreehari Surendran Rajasree†,Jierui Yu†,Saied Md Pratik,Xinlin Li,Rui Wang,Amar S Kumbhar,Subhadip Goswami,Christopher J Cramer,Pravas Deria
Journal
Journal of the American Chemical Society
Published Date
2022/1/14
Factors affecting the mechanism of 1, 3-butadiene polymerization at open metal sites in Co-MFU-4l
Selective polymerization of 1,3-butadiene to form 1,4-cis-polybutadiene (PBD) is a fundamental challenge in the modern rubber industry. However, current industrial heterogeneous catalysts cannot offer extremely high (>99%) 1,4-cis selectivity. Recently, the Dincă group reported a highly stereoselective polymerization of 1,3-butadiene using a transition-metal loaded metal-organic framework (MOF) catalyst Co(II)-MFU-4l ( J. Am. Chem. Soc. 2017, 139, 12664−12669). We here undertake a computational investigation on the reaction mechanism of 1,3-butadiene polymerization catalyzed by this MOF-based catalyst, and our density functional theory (DFT) calculations suggest that missing-linker defects at the Co(II) nodes are essential for the experimentally observed high 1,4-cis-polybutadiene (PBD) selectivity. We find that a suitably low-energy 1,4-cis-π-insertion transition state requires four empty coordination …
Authors
Huiling Shao,Riddhish Pandharkar,Christopher J Cramer
Journal
Organometallics
Published Date
2022/1/7
Localized Active Space-State Interaction: a Multireference Method for Chemical Insight
Multireference electronic structure methods, like the complete active space (CAS) self-consistent field model, have long been used to characterize chemically interesting processes. Important work has been done in recent years to develop modifications having a lower computational cost than CAS, but typically these methods offer no more chemical insight than that from the CAS solution being approximated. In this paper, we present the localized active space-state interaction (LASSI) method that can be used not only to lower the intrinsic cost of the multireference calculation but also to improve interpretability. The localized active space (LAS) approach utilizes the local nature of the electron–electron correlation to express a composite wave function as an antisymmetrized product of unentangled wave functions in local active subspaces. LASSI then uses these LAS states as a basis from which to express complete …
Authors
Riddhish Pandharkar,Matthew R Hermes,Christopher J Cramer,Laura Gagliardi
Journal
Journal of Chemical Theory and Computation
Published Date
2022/10/18
Professor FAQs
What is Christopher J. Cramer's h-index at University of Minnesota-Twin Cities?
The h-index of Christopher J. Cramer has been 70 since 2020 and 115 in total.
What are Christopher J. Cramer's top articles?
The articles with the titles of
Mechanistic insights into radical formation and functionalization in copper/N-fluorobenzenesulfonimide radical-relay reactions
Radical ring-opening polymerization of sustainably-derived thionoisochromanone
Understanding Antiferromagnetic and Ligand Field Effects on Spin Crossover in a Triple-Decker Dimeric Cr (II) Complex
Correction: Radical ring-opening polymerization of sustainably-derived thionoisochromanone
Metal–Carbodithioate-Based 3D Semiconducting Metal–Organic Framework: Porous Optoelectronic Material for Energy Conversion
Superradiance and Directional Exciton Migration in Metal–Organic Frameworks
Factors affecting the mechanism of 1, 3-butadiene polymerization at open metal sites in Co-MFU-4l
Localized Active Space-State Interaction: a Multireference Method for Chemical Insight
...
are the top articles of Christopher J. Cramer at University of Minnesota-Twin Cities.
What are Christopher J. Cramer's research interests?
The research interests of Christopher J. Cramer are: Chemistry, Catalysis, Theoretical Chemistry, Physical Chemistry
What is Christopher J. Cramer's total number of citations?
Christopher J. Cramer has 79,959 citations in total.
What are the co-authors of Christopher J. Cramer?
The co-authors of Christopher J. Cramer are Donald Truhlar, Joseph Hupp, Omar Farha, Lawrence Que, Jr..