We have conducted the first study of the use of terahertz radiation to precisely identify pre-melting, melting,
polymerization, depolymerization and the influence of polar water in sulfur by scanning frequency as a parametric
function of temperature, and including identifying precursor and intermediate states. This spectroscopic study has also
identified the orthorhombic-monoclinic phase transformation, and the melting of the superheated orthorhombic phase.
This work also reports detection of a water absorption indicating a perturbation of the water molecules, associated with
solvation spheres of the inter-chain dynamics, as a precursor to a transition, and supporting our earlier results showing
the transducing capabilities of conglomerates of water molecules. Through a study of the fine structure of the water
absorption, we are able to determine information about local polarization effects which contribute to the transducing
properties of water relative to a ligand. The above inorganic polymer study is applied to the understanding of the
response of biomolecules to thermal and chemical influences, and data are included giving optical, electrical, and pH
properties of the DNA-water system, showing a major conformational transition at ~43°C, and various forms of reconformation
of DNA macromolecule due to chemical perturbation. Our results include findings aimed at
complementing existing inhibitors that are intended to prevent retrovirus/phage invasion of the host cell DNA.
We have studied the liquid-liquid allotropic transitions in molten sulfur using terahertz
(THz) spectroscopy. Liquid sulfur is selected as an initial choice of materials because its
structure and properties are well established from previous in-situ studies by one of the
current investigators (and by other researchers) using a variety of physical and chemical
methodologies. It is known that sulfur melts to an equilibrium mixture of octameric (S8)
rings and short chains, with a small concentration of hexameric rings (S6). As
temperature is increased, thermal energy initiates ring scission and the resulting
diradically-terminated short chains undergo covalent bonding to induce polymerization at
159-166°C. Further increase in temperature causes an increase in chain length and an
increase in chain species concentration until a temperature of 188°C is reached at which
the long chains (~106 atoms in length) undergo chain scission, and although the chains
start to break up, the polymer concentration of the mixed phases still increases. We have
experimentally mapped THz absorption, transmission, and reflection/scattering effects
with these known transitions in liquid sulfur, as a function of temperature and
wavelength.
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