Saturday, July 14, 2012

Halogens

In ancient Greece Lepiccus and Democritus suggested a model in which atoms colliding randomly in space create clumps that differ from each other even they are made of the same undivided particles and that these clumps give matter the attributes we observe such as hardness, smell, color and so on. The model they figured out simply by thinking without any possibility of experimentally studying atoms strikingly resembles the atomic theory of today and not by chance are these particles called by the name they coined. The clumps of atoms contain the idea of molecules which are combinations of atoms.

Modern atomic theory understands that atoms are not identical building blocks but contain different number of protons, neutrons and electrons in their cores which can also be divided. But perhaps we may forgive Democritus for not figuring that out. Periodic table is a classification of the known materials that consist of "clumps" in the cores. Astronomers call all elements metals that are heavier than hydrogen and helium with one and two protons in the nucleus.  

The enormous world of molecule "clumps" is way more complicated than the single atomic model thought out by these ancient Greek natural philosophers and there is nothing random about them. But the challenge of the genius of the past still remains: despite of the enormous advances in studying the building blocks God of Israel has used to build the world we still have almost know idea how atomic and molecular structures and "clumps" translate into attributes of matter.

How come that the position of an element in the periodic table also defines its state? Why is helium gas and carbon "metal" (astronomers call "metals" all elements that are heavier than helium).

Work goes on in studying matter and recently there has been particular interest in halogens
The halogens or halogen elements are a series of nonmetal elements from group 17 of the periodic table, comprising fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At). The artificially created element 117 (ununseptium), may also be a halogen. The group of halogens is the only periodic table group which contains elements in all three familiar states of matter at standard temperature and pressure.

Halogen bonding (XB) is the non-covalent interaction that occurs between a halogen atom (Lewis acid) and a Lewis base. Although halogens are involved in other types of bonding (e.g. covalent), halogen bonding specifically refers to when the halogen acts as an electrophilic species.
wikipedia
Top research on molecular bonding
State of Finland supports outstanding scientists by appointing them to four year post of an Academy Professor. Kari Rissanen Ph.D. FRSC from Jyväskylä University Department of Chemistry was recently chosen for a rare consecutive second term. What is particularly interesting in his work is the central role halogen bonding has in advancing science.We see also from this work that understanding how structure and bonding affect the properties of matter is not all that simple.
Kari Rissanen has been Academy Professor in 2008–2012 at the University of Jyväskylä and has now been re-appointed for a second term. His research field is supramolecular chemistry, nanochemistry and X-ray crystallography. Within supramolecular chemistry, Rissanen is a well-renowned expert, both in structural research and synthetics. The focus of his research is on weak intermolecular interactions in solid state materials, solutions and gaseous phases. Special attention is paid to hydrogen and halogen bonds and the coordination chemistry of transition metals. The novel nano- and supramolecular systems that Rissanen has constructed are built on weak intermolecular interactions. Halogen bonding is a relatively new concept, and Rissanen’s contribution has been crucial to understanding its mechanisms and potential to use it.

Rissanen’s aim is to construct novel encapsulated supramolecules by applying metal coordination or halogen bonding and new halogen-bonded and organic two- or three-dimensional frameworks. These new lines of inquiry are expected to result in major advances and breakthroughs in supramolecular chemistry and nanochemistry.
Finnish Academy
In 2010 the work of the international team to which Rissanen belongs and which is led by professor Virgil Percec from Pennsylvania University was chosen as one of the scientific break-throughs in Chemistry : Self-Assembly of Janus Dendrimers into Uniform Dendrimersomes and Other Complex Architectures (Science)

Hopefully, research in halogen bonding will help humanity some day to understand how the structures of atoms and molecules determine their chemical and other characteristics. We can catalogue the attributes associated with structures and explain their functioning but where is the binding between the two, why bromium smells so bad?

Halogens and Theology?
You may, of course, ask what Theology has to do with all this? Well, to put it shortly, neither Victor nor Kari invented halogens, they are researching it and how it can be used and produced - but it is God of Israel who has created everything, including halogens, and His wisdom is so obvious in the making of these elements that we humans are really hard pressed in trying to catch up with that thinking. Theology reminds us of the Biblical truth and invites all of us to praise the One, who created these rather strange elements.

Tobit 12:7: It is honourable to reveal and confess the works of God.

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