Nuclear Magnetic Resonance Spectroscopy - Lab Report Example

Lab report using NMR al affiliation) The aim of the experiment is to determine the structure of C10H18O molecule through utilization of the NMR spectrum which has proved to a significant utility in elucidation of molecular structure since the properties displayed can be associated with the chemical perception of the molecular structure. The chemical shift targeting each nucleus can be correlated to the chemical environment with the scalar coupling showing an indirect interaction between the individual nuclear that are mediated by the electrons found in the chemical bond and appropriate conditions, the number of the nuclei are related to the area of the resonance. Hydrogen molecule found in the hydro carbon is the most frequently observed nuclear in the NMR spectroscopy (Orrell, Šik & Stephenson, 2010). Introduction A 2D nuclear magnetic resonance spectroscopy experiments entails a set of NMR methods which offer data that has been plotted in a space which is defined by 2 frequency axes and not a single one. The Methods of NMR that will be utilized in the experiment entails correlation spectroscopy, nuclear overhauser effect spectroscopy and the hetero nuclear single quantum correlation spectroscopy. Hetero nuclear single quantum correlation spectroscopy will detect the correlation between the nuclei of 2 different types that are divided by a bond. The method often presents a single peak per pair. The original two dimensional experiments were utilized to identify the nuclei which shared a scalar coupling. The presence of the off-diagonal often correlates the coupled partners (Orrell, Šik & Stephenson, 2010). Procedures The procedure is first conducted by collecting a sample of nuclear magnetic resonance spectrometer that will be sufficient soluble in the solvent that was requested. The samples were prepared in solid, semi-solid or NMR chromatography. The sample was collected in 5mm nuclear magnetic resonance spectrometer. The tubes were labeled with the significant concentric label. The purpose of the tubes being labeled was to ensure that the experiment is curried out sufficiently. The sample collected was sufficient enough to yield better results for the experiment since it was able to form the chromatography. In the C10H18O experiment, the experiment is often utilized to analyze coupling relationships between the protons. Clear solutions have been identified to offer the best results with turbid solutions presenting poor spectrum. To achieve the maximum solution, the solvent with the low viscosity was chosen (Orrell, Šik & Stephenson, 2010). In cases where the signal made by the solvent fails to function, a different solvent should be utilized in the process. Having selected the solvent containing the hydro carbon, one should ensure that NMR tube, the solvent, the sample and anything which comes into contact with the system is prevented. Abrasive cleaners and brush should not be used to clean the tube as it may reduce spectral resolution. Individuals are allowed to clean the tube by using a cotton wool that was wrapped on a stick. The sample used in the experiment was free from dust participles, fibers and precipitate which may end up interfering with the sample though filtration. The tube was closed with the Teflon tape and afterwards it will be followed by the cap. The result of the sample was out after 20 minutes and I was able to interpreted accordingly Results and discussions The result of the experiment was interpreted and represented as follows.     Zones     1 2 3 4 5 Outcome Present Alcohol O-H Aryl C-H, Aldehyde Peak Carbonyl Group C=C   Absent C-H       C=C The first the peak revealed the presence of an alcohol 0-H, the amine N-H was absent as well as the =C-H as a result of absence of a peak in Zone three. Zone 2 revealed the presence of aryl C-H bond as a result of the presence of the peak, with the presence of carboxylic C-H and aldehyde present. Zone 4 indicated the presence of the carbonyl group C=C due to the presence of peak. The benzene C=C was absent in zone five due to lack of the peak. The height of the peak was around 5cm-1. The second peak revealed the presence of C-C bond .The compound obtained was colorless oil with a molecular weight of (C10H18O) based on the molecular ion peaks that was observed. As shown in the figure below The hydrogen nuclei is the most frequently observed in the NMR spectroscopy. Hydrogen atom is found in most organic compounds with the proton having high intrinsic sensitivity as well as being a hundred percent in nature. The spectrum presents a wealth of coupling information and chemical shifts and is the beginning point for most of the experiments utilized in determination of various structures. The appearance of the multiplet fine structure on the resonance of NMR is as a result of the presence of scalar coupling associated with another nuclear. Such types of coupling often occur over 2 or 3 bonds (Orrell, Šik & Stephenson, 2010). The COSY experiment often provides a mean of identifying equally coupled protons that are extensively utilized in the two dimensional experiment. The use is often significant when the homonuclear decoupling experiment is considered unsuitable such as in areas that involves complex spectra where the selective decoupling is considered difficult to be conducted as a result of resonance overlap. The COSY experiment is suitable for establishing connectivity in cases of large coupling network (Orrell, Šik & Stephenson, 2010). The experiment often present a two dimensional contour map with each dimension representing contours that represents the intensity of the signals as well as the proton chemical shift. The diagonal shows peaks which corresponds to the usual ID spectrum with no new information. The peaks of interest for the experiment were the cross peaks or the ones that are off-diagonal. The spectrum is often symmetrical with the diagonal coupling from B to A and then from A to B. Conclusion The nuclear magnetic resonance spectrometer procedure is the best procedure that has helped to determine the structure of the hydrocarbon C10H18O though utilization of various techniques such as correlation spectroscopy, nuclear overhauser effect spectroscopy and the hetero nuclear single quantum correlation spectroscopy in determining the structure of the hydrocarbon (Orrell, Šik & Stephenson, 2010). Reference Orrell, K., Šik, V., & Stephenson, D. (2010). Quantitative investigations of molecular stereodynamics by 1D and 2D NMR methods. Progress In Nuclear Magnetic Resonance Spectroscopy, 22(2), 141-208. doi:10.1016/0079-6565(90)80004-2 Read More