Crystalline Complex Formation

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  • Topic: Crystal, Supramolecular chemistry, Solid
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Crystalline Complex Formation

Christine Orobiaa, John Anthony Pobleteb, Mary Janzel Prieto*

College of Pharmacy, Adamson University, Manila Phillipines
College of Pharmacy, Adamson University, Manila Philippines

Date submitted: January 25, 2013

Abstract

In this experiment we needed again to gain crystals. The increased affinity towards complex formation exhibited by metal ions with an unfilled d-shell is related to the crystal field stabilization of such compounds and furnishes an explanation of what is the basis of the so-called Irving-Williams rule. The orbital degeneracy of the ground term determines the symmetry of the configuration and is thus responsible for irregularities in the complexity constants. In this experiment, we want to show how many grams of thiourea that we gain. The first thing that we do was mixing the thiourea and anhydrous methanol we dissolved the compound and put on the hot to warmed add a few drops of carbon tetra chloride-octanol when you see that the crystals filter it. After this things put it inside the oven and left it to an hour after an hour we weigh it again and solved for the percentage recovery. Keywords: anhydrous methanol; thiourea; carbon tetra-chloride

Introduction

Crystalline inclusion complexes represent an intriguing class of supramolecular assembly that continues to receive considerable attention. The rational design of composite solid state materials has many potential applications in areas such as chemical preparation, crystals engineering and non linear optics. One tactic commonly employed in the synthesis of potential inclusion hosts is the incorporation of functional groups known to participate in relatively strong hydrogen bonding interactions (such as O-H, N-H and CO2H moieties) into rigid and bulky molecular frameworks. The presence of symmetry elements within the lot of crystals that seems like needle appearance. Those crystals that formed above the filter paper is called the sublimate product and when you removed the filter paper that covered the dish you will see the another crystals formed and it is called the residue. After collecting the crystals we get a pinch of it for the completeness of the separation we sublimate it in 1 mL of hot distilled water and a few drops of barium chloride. When we already done with that procedure we host structure also has been identified as a positive attribute. Examples of efficacious inclusion hosts designed in accordance with the strategy certain alicylic diols, diarylmethanol derivatives “scissors” shaped hosts, “roof” shaped hosts and thienothiophene derivatives. These inclusion hosts form supramolecular assemblies with suitable guests either through direct hosts-guest interaction(e.g, hydrogen bonding) or through the formation of well- defined voids within the crystal lattice that are occupied by included guest molecules. In recent years the study of crystalline inclusion compounds devoid of functional groups capable engaging in strong hydrogen bonding interactions has acquired increased significance. In certain instances, such as inclusions complexes exhibit host-guest interactions mediated relatively weak hydrogen bonding. While the existence of solid state hydrogen bond has been the subject of some controversy, a considerable amount of empirical and computational evidence has been accumulated that lends credence to the notion of structurally defining non covalent C-H…O interactions. Indeed, it has been postulated that in certain cases numerous C-H…O interactions can override stronger O-H…O and N-H… bonding motifs. It is however, generally regarded as much more difficult to design solid state networks assembled via C-H...O hydrogen bonds. Thus, the identification and preparation of new inclusion hosts that utilize C-H…O interactions may provide valuable insight relevant to the rational design of new functional solid state supramolecular complexes.

Methods

Crystals are solid...
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