Tag : spectroscopy

Investigating Polyphosphates with 31P NMR Spectroscopy

Abstract The experiment investigated the use of 31P NMR spectroscopy to determine the structure of polyphosphate anions. The structures of two cyclic (P4O124- and P3O93-) and two linear (P3O105- and P2O74-) were found. Introduction Phosphorus (V) has many polyphosphate oxo-anions which usually existing as either linear or cyclic phosphates. It is known that the linear phosphates are of the form [PnO3n+1](n+2)- and the cyclic phosphates in the form [PnO3n]n- (1). Two of these were synthesised: P3O105- and P4O124- using the […]

IDENTIFICATION OF STEREOCHEMICAL (GEOMETRICAL) ISOMERS OF [Mo(CO)4(L)2] BY IR SPECTROSCOPY.

IDENTIFICATION OF STEREOCHEMICAL (GEOMETRICAL) ISOMERS OF [Mo(CO)4(L)2] BY IR SPECTROSCOPY. INTRODUCTION Metal carbonyl complexes are of interest in inorganic chemistry as they are good starting materials for many low oxidation state compounds. They are very reactive and lose one or more CO ligands upon heating, photolysis, exposure to other radiation, partial oxidation etc. They react with Lewis bases to form closed shell compounds and can also form clusters. Phosphine complexes (as in this experiment) are also used in many catalytic […]

Spectra and Molecular Structure – HCl & DCl

Spectra and Molecular Structure – HCl & DCl By: Christopher T. Hales ABSTRACT: FTIR spectroscopy was used to analyze rotational-vibrational transitions in gas-state HCl and DCl and their isotopomers (due to 35Cl and 37Cl) to determine molecular characteristics. Energy transitions from the spectra were plotted vs. frequency, from which several physical constants were determined. These constants were then used to determine the force constants, H35Cl=527667(error) dynes/cm, H37Cl=527781(error) dynes/cm, D35Cl=522901(error) dynes/cm, and D37Cl=521422(error) dynes/cm; and equilibrium bond length, H35Cl=1.274(error)Å, H37Cl=1.275(error)Å, D35Cl=1.201(error)Å, D37Cl=1.202(error)Å. […]

Natural Sciences / Physics 9:10 pm , January 17, 2018 0

Determination of Manganese in Steel

By: Juno Kim and Nicole Introduction The goal of this experiment was to determine the mass percent of manganese in an unknown steel sample using methods of visible spectroscopy and volumetric analysis. The two methods were then analyzed and compared to decide the better method for determining the composition of Mn in the unknown steel. In both methods, the unknown steel was digested in hot concentrated Nitric acid, HNO3, and analyzed for transition metals. An accurate analysis of steel […]

Chemisty / Natural Sciences 9:11 pm , April 17, 2014 0

VIBRATION-ROTATION SPECTROSCOPY OF HCl

VIBRATION-ROTATION SPECTROSCOPY OF HCl By: John Ricely Abstract Using the Nicolet 6700 spectrometer, the spectrum for HCl was analyzed. There were two branches that were apparent in the result of the spectroscopy, the R branch and the P branch, that correspond to ∆J= +1 and ∆J= -1, respectively. Each peak, differentiating between 35Cl and 37Cl, is assigned an m value and then plotted with wavenumber vs. m value. Analytical software is used to derive an equation of the line […]

Chemisty / Natural Sciences 3:06 pm , April 1, 2014 0

Synthesis and Spectroscopy of Eu(III) and Tb(III) diketonate complexes

Written by Alex Abstract The purpose of this experiment is to determine the electron energy transitions on Europium and Terbium complexes with tmh. This was determined by finding the wavelengths of the peaks in an emission spectrum of those complexes. It was found that the largest peak of the Europium complex was at 614 nm, and the largest peak of the Terbium complex was at 547 nm. Introduction In order to understand photochemistry, one must understand the basics of atomic […]

Chemisty / Natural Sciences 10:34 pm , November 21, 2013 0

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