Monday, April 18, 2011

MOFs are starting to kill me...

A glass of Chardonnay.
Maroon 5.
OPI's "Pinking of You." (my new favorite sheer pink)
Thesis?
If only the last part was done...
Here's the very first part of my introduction if you feel like reading it.  You'll probably read the first two sentences and then be bored to tears because you don't care about metal organic frameworks (MOFs)...  If I have any chemistry, or biochem majors reading my blog, you might enjoy it!


Metal organic frameworks (MOFs) can be defined as a type of crystalline hybrid material that have a crystal structure which is comprised of an extended network of metal ions or small clusters connected through rigid organic spacers, known as the coordinating ligands (1-2).  When MOFs are organized into three dimensional structures, the building units coordinate together allowing for a regular pattern and therefore a network of uniform pores and channels within the framework (1).  This porous characteristic is the basis of interest in MOFs today because the available free space can be occupied by host molecules at an extremely high rate (up to 90% of the crystal volume in some cases) (1).  Such porosity of the MOF can be manipulated through the choice of organic linkers and metal coordination geometry (1).  The organic building blocks from which MOFs are constructed allow for the synthesis of an infinite number of new materials with diversity in structure and porosity (4).  Because MOFs offer the ability to absorb or store host molecules and the flexibility to accommodate different molecules through calculated manipulation, they are ideal units with which to address key applications such as hydrogen storage, enhanced catalysis, chemical/molecular sensors, drug delivery, and gas purification/gas separation to name a few (3).
One metal organic framework of particular interest is the porphyrin unit.  The porphyrin unit is considered to be quite useful because it is a rigid metalloligand that offers an additional approach to control the structure of a MOF (5).  Porphyrin based linkers are set apart from other metalloligands in that the cavity inside the porphyrin is able to adopt a variety of metal elements allowing  for additional coordination capacity with which to manipulate framework topology (6-7).  This characteristic also provides the porphyrin with the ability to self-assemble into framework architectures without relying on external connectors (8).  Another important feature of porphyrin molecules is that they contain a rigid square-planar geometry with multiple molecular recognition sites ideal for metal coordination (or hydrogen bonding) and thus contain an extensive supramolecular chemistry (8).  The specific porphyrin molecule used throughout this study is meso-tetra(carboxyphenyl)porphyrin (TCPP).

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