Show Advanced Search


Containing Text
- - -
Filter by author or institution
Filter by publication date
October, 2006
Filter by journal section

Filter by science education

Transition Temperature: The temperature at which a substance changes from one state or conformation of matter to another.

Molecular Orbital (MO) Theory

JoVE 10447

Source: Tamara M. Powers, Department of Chemistry, Texas A&M University

This protocol serves as a guide in the synthesis of two metal complexes featuring the ligand 1,1'-bis(diphenylphosphino)ferrocene (dppf): M(dppf)Cl2, where M = Ni or Pd. While both of these transition metal complexes are 4-coordinate, they exhibit different geometries at the metal center. Using molecular orbital (MO) theory in conjunction with 1H NMR and Evans method, we will determine the geometry of these two compounds.

 Inorganic Chemistry

Sputter Growth and Characterization of Metamagnetic B2-ordered FeRh Epilayers

1School of Physics and Astronomy, University of Leeds, 2Institute of Materials Research, University of Leeds, 3School of Chemistry, University of Edinburgh, 4Department of Chemical Engineering, Northeastern University, 5Department of Physics, Northeastern University

JoVE 50603


Electric-field Control of Electronic States in WS2 Nanodevices by Electrolyte Gating

1Quantum-Phase Electronics Center (QPEC) and Department of Applied Physics, The University of Tokyo, 2Materials Sciences Division, Lawrence Berkeley National Laboratory, 3Institute of Scientific and Industrial Research, Osaka University, 4RIKEN Center for Emergent Matter Science (CEMS)

Video Coming Soon

JoVE 56862

 JoVE In-Press

Synthesis of Thermogelling Poly(N-isopropylacrylamide)-graft-chondroitin Sulfate Composites with Alginate Microparticles for Tissue Engineering

1Department of Chemical Engineering, Rowan University, 2Department of Biological Sciences, Rowan University, 3Department of Biomedical Engineering, Drexel University

JoVE 53704


An Enzyme- and Serum-free Neural Stem Cell Culture Model for EMT Investigation Suited for Drug Discovery

1Dept. of Biomedicine, Pharmacenter, University of Basel, 2Molecular Signalling and Gene Therapy, Narayana Nethralaya Foundation, Narayana Health City, 3Brain Ischemia and Regeneration, Department of Biomedicine, University Hospital Basel, 4Department of Neurosurgery, Klinikum Idar-Oberstein, 5Department of Neurosurgery and Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, 6Department of Neurology, Laboratory of Molecular Neuro Oncology, University Hospital of Zurich

JoVE 54018

 Developmental Biology

Induction of Mesenchymal-Epithelial Transitions in Sarcoma Cells

1Department of Medicine, Duke University, 2Department of Bioengineering, Rice University, 3Department of Molecular Genetics and Microbiology, Duke University, 4Solid Tumor Program and the Duke Prostate Center, Duke University Medical Center, 5Duke University Medical Center

JoVE 55520

 Developmental Biology

Characterization of Electrode Materials for Lithium Ion and Sodium Ion Batteries Using Synchrotron Radiation Techniques

1Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory, 2Department of Chemistry, University of Illinois at Chicago, 3Stanford Synchrotron Radiation Lightsource, 4Haldor Topsøe A/S, 5PolyPlus Battery Company

JoVE 50594


Nanomanipulation of Single RNA Molecules by Optical Tweezers

1Nanoscale Engineering Graduate Program, College of Nanoscale Science and Engineering, University at Albany, State University of New York, 2Nanoscale Science Undergraduate Program, College of Nanoscale Science and Engineering, University at Albany, State University of New York, 3Nanobioscience Constellation, College of Nanoscale Science and Engineering, University at Albany, State University of New York, 4The RNA Institute, University at Albany, State University of New York, 5Department of Biological Sciences, University at Albany, State University of New York

JoVE 51542


The Evans Method

JoVE 10304

Source: Tamara M. Powers, Department of Chemistry, Texas A&M University 

While most organic molecules are diamagnetic, wherein all their electrons are paired up in bonds, many transition metal complexes are paramagnetic, which has ground states with unpaired electrons. Recall Hund's rule, which states that for orbitals of similar energies, electrons will fill the orbitals to maximize the number of unpaired electrons before pairing up. Transition metals have partially populated d-orbitals whose energies are perturbed to varying extents by coordination of ligands to the metal. Thus, the d-orbitals are similar in energy to one another, but are not all degenerate. This allows for complexes to be diamagnetic, with all electrons paired up, or paramagnetic, with unpaired electrons. Knowing the number of unpaired electrons in a metal complex can provide clues into the oxidation-state and geometry of the metal complex, as well as into the ligand field (crystal field) strength of the ligands. These properties greatly impact the spectroscopy and reactivity of transition metal complexes, and so are important to understand. One way to count the number of unpaired electrons is to measure the magnetic susceptibility, χ, of the coordinatio

 Inorganic Chemistry

Single-molecule Manipulation of G-quadruplexes by Magnetic Tweezers

1School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, 2Mechanobiology Institute, National University of Singapore, 3Department of Physics, National University of Singapore, 4Research Institute for Biomimetics and Soft Matter, Fujian Provincial Key Lab for Soft Functional Materials Research, Department of Physics, Xiamen University, 5Center for Bioimaging Sciences, National University of Singapore

JoVE 56328


More Results...