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Quantum mechanics explains efficiency of photosynthesis

By Guest PostJanuary 9, 2014Sciencealexandra olaya castro, chromophore vibrations, classical physics, clover leaf, efficiency of photosynthesis, energy transfer, light gathering macromolecules, molecular vibrations, non classical explanation, quantum, quantum mechanics, quantum of energy, quantum physics, quantum states, scott robinson, theoretical evidence, vibrational degrees

Light-gathering macromolecules in plant cells transfer energy by taking advantage of molecular vibrations whose physical descriptions have no equivalents in classical physics, according to the first unambiguous theoretical evidence of quantum effects in photosynthesis published today in the journal Nature Communications.

The majority of light-gathering macromolecules are composed of chromophores (responsible for the colour of molecules) attached to proteins, which carry out the first step of photosynthesis, capturing sunlight and transferring the associated energy highly efficiently. Previous experiments suggest that energy is transferred in a wave-like manner, exploiting quantum phenomena, but crucially, a non-classical explanation could not be conclusively proved as the phenomena identified could equally be described using classical physics. (more…)

Secret of Scent Lies in Molecular Vibrations

By Guest PostFebruary 2, 2013General, Sciencealexander fleming, athens, atom, bonds, british chemist, bsrc, chemists, cyclopentadecanone, deuterium odorants, electron cloud, Greece, hydrogen atom, hydrogen musk molecules, inelastic electron tunnelling, lcn, luca turin, malcolm dyson, mass, molecular shape, molecular vibrations, nano scale changes, quantum mechanism, secret of scent, simon gane, spectroscope, ucl scientists, vibration of molecule

Molecular vibrations, rather than molecular shape, give substances their distinct smell according to a new study by UCL scientists.

In a study designed to find out how smell is written into a molecule’s structure, scientists tested whether changing how a molecule vibrates on a nano-scale changes its smell.

Molecules are made of atoms connected by bonds. The arrangement of bonds and atoms defines the vibration of the molecule. Chemists can therefore identify molecules by their vibrations, using a spectroscope. (more…)

Nanocrystals Go Bare: Berkeley Lab Researchers Strip Material’s Tiny Tethers

By Guest PostDecember 12, 2011Scienceanna llordes, april sawvel, berkeley lab, brett helms, carbon hydrogen bonds, chemical solution, delia milliron, devices, diodes, electronic conductivity, energy storage, environments, evelyn rosen, hydrocarbon, ink jet printer, lawrence berkeley national laboratory, ligand free nanocrystal, ligands, meerwein salt, metal oxides, metallic, molecular foundry, molecular vibrations, naked nanocrystals, nano ir, nanocrystal, nanoscale infrared spectroscopy, orders of magnitude, organic compound, organic ligands, organometallic molecules, oxidizing agents, photovoltaics, raffaella buonsanti, selenide nanocrystal, semiconductors, smart windows, solar fuels, spin, spray coating, stripping nanocrystals, strong acids, supercapacitor materials, surface ligands, tether like molecules, triethyloxonium tetrafluoroborate, universal technique, unstripped nanocrystal films, variety of applications

Researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) have discovered a universal technique for stripping nanocrystals of tether-like molecules that until now have posed as obstacles for their integration into devices. These findings could provide scientists with a clean slate for developing new nanocrystal-based technologies for energy storage, photovoltaics, smart windows, solar fuels and light-emitting diodes.

Nanocrystals are typically prepared in a chemical solution using stringy molecules called ligands chemically tethered to their surface. These hydrocarbon-based or organometallic molecules help stabilize the nanocrystal, but also form an undesirable insulating shell around the structure. Efficient and clean removal of these surface ligands is challenging and has eluded researchers for decades. (more…)

Tag Archives: molecular vibrations

Quantum mechanics explains efficiency of photosynthesis

Secret of Scent Lies in Molecular Vibrations

Nanocrystals Go Bare: Berkeley Lab Researchers Strip Material’s Tiny Tethers