Michael Ruggiero
@mikerug.bsky.social
340 followers
130 following
66 posts
Chemistry and Chemical Engineering Professor at the University of Rochester.
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Michael Ruggiero
@mikerug.bsky.social
· Nov 15
Toward On-Demand Polymorphic Transitions of Organic Crystals via Side Chain and Lattice Dynamics Engineering
Controlling polymorphism, namely, the occurrence of multiple crystal forms for a given compound, is still an open technological challenge that needs to be addressed for the reliable manufacturing of crystalline functional materials. Here, we devised a series of 13 organic crystals engineered to embody molecular fragments undergoing specific nanoscale motion anticipated to drive cooperative order–disorder phase transitions. By combining polarized optical microscopy coupled with a heating/cooling stage, differential scanning calorimetry, X-ray diffraction, low-frequency Raman spectroscopy, and calculations (density functional theory and molecular dynamics), we proved the occurrence of cooperative transitions in all the crystalline systems, and we demonstrated how both the molecular structure and lattice dynamics play crucial roles in these peculiar solid-to-solid transformations. These results introduce an efficient strategy to design polymorphic molecular crystalline materials endowed with specific molecular-scale lattice and macroscopic dynamics.
pubs.acs.org
Michael Ruggiero
@mikerug.bsky.social
· Sep 8
Michael Ruggiero
@mikerug.bsky.social
· Sep 4
Experimentally Mapping the Molecular Pathways and Intermolecular Forces that Drive Elasticity in Flexible Crystals
Elastically flexible molecular crystals are an emerging class of advanced materials, driving innovation in fields ranging from electronics to medicinal applications. At the fundamental level, bulk mat...
chemrxiv.org
Michael Ruggiero
@mikerug.bsky.social
· Jun 11
Michael Ruggiero
@mikerug.bsky.social
· May 20
Local coordination geometry within cobalt spinel oxides mediates photoinduced polaron formation
Understanding the photophysics of transition metal oxides is crucial for these materials to realize their considerable potential in applications such as photocatalysis and optoelectronics. Recent stud...
pubs.rsc.org
Michael Ruggiero
@mikerug.bsky.social
· May 16
Exploring the Interplay of Lattice Dynamics and Charge Transport in Organic Semiconductors: Progress Towards Rational Phonon Engineering
Organic semiconductors (OSCs) have garnered significant attention due to their potential in flexible, lightweight, and cost-effective electronic devices. Despite their promise, the assembly of organi...
onlinelibrary.wiley.com
Michael Ruggiero
@mikerug.bsky.social
· Apr 8
Solving the Cellulose I Polymorphic Structural Riddle: Disorder in Hydrogen Bond Networks Activates Diagnostic Terahertz Dynamics
Cellulose is a common polymer found in natural sources, with the potential to be used in a wide variety of green and technologically-relevant applications. Despite years of effort, the precise 3D stru...
chemrxiv.org
Michael Ruggiero
@mikerug.bsky.social
· Mar 28
Michael Ruggiero
@mikerug.bsky.social
· Mar 13
Michael Ruggiero
@mikerug.bsky.social
· Mar 11
Anharmonic Vibrational States of Double-Well Potentials in the Solid State from DFT Calculations
We introduce a general approach for the simulation of quantum vibrational states of (symmetric and asymmetric) double-well potentials in molecules and materials for thermodynamic and spectroscopic applications. The method involves solving the nuclear Schrödinger equation associated with a one-mode potential of the type V(Q) = aQ2 + bQ3 + cQ4 (with a < 0 and c > 0) and thus explicitly includes nuclear quantum effects. The potential, V(Q), is obtained from density functional theory (DFT) calculations performed at displaced nuclear configurations along the selected normal mode, Q. The strategy has been implemented into the Crystal electronic structure package and allows for (i) the use of many density functional approximations, including hybrid ones, and (ii) integration with a quasi-harmonic module. The method is applied to the spectroscopic characterization of soft lattice modes in two phases of the molecular crystal of thiourea: a low-temperature ferroelectric phase and a high-temperature paraelectric phase. Signature peaks associated with structural changes between the two phases are found in the terahertz region of the electromagnetic spectrum, which exhibit strong anharmonic character in their thermal evolution, as measured by temperature-dependent terahertz time-domain spectroscopy.
pubs.acs.org
Michael Ruggiero
@mikerug.bsky.social
· Jan 10
Connecting lattice and molecular vibrations to organic crystal properties
Understanding dynamic processes in molecular crystals is becoming crucial for the development of next-generation smart crystalline materials. In this context, Zwolenik & Makal [(2025). IUCrJ, 12, 23–3...
journals.iucr.org