The product obtained had a melting point of approximately 128-130 °C and a weight of .054 grams. The limiting reagent was calculated to be sodium borohydride. With the weight and limiting reagent, the percent yield was calculated to be approximately 53.33%. The IR of the product showed a peak at approximately 3311.25, which indicates the presence of an O-H bond.
This paper describes the methods used in the identification, investigation of properties, and synthesis of an unknown compound. The compound was identified as calcium nitrate by a variety of tests. When the compound was received, it was already known to be one of twelve possible ionic compounds. The flame test identified the presence of the calcium anion in the compound. The compound tested positive for the nitrate cation using the iron sulfate test. At this point it was hypothesized that the compound was calcium nitrate. Reactivity tests and quantitative analysis comparing the unknown compound with calcium nitrate supported this hypothesis. Synthesis reactions were then carried out and analyzed.
Procedure: Refer to pages 67-76 of General Chemistry 1210: General Chemistry Laboratory Manual by the Department of Chemistry, The Ohio State University, Hayden-McNeil Publishing, 2016.
This could be improved by utilizing an inert atmosphere of solely nitrogen. Melting the compound resulted in an intensely dark purple liquid. This is a result of the resonance stabilized radical being formed by the homolysis of the carbon-to-carbon bond validating the photochromic properties. The colour change further substantiates that the desired product was produced despite the inaccuracies in melting point values. Homolytic cleavage of the dimer prepared by solvation with toluene results in a deep purple solution confirming the formation of the resonance stabilized radical.
There are four main regions of IR absorptions: region 4000 – 3000 cm-1 corresponds to N-H, C-H and O-H stretching, region 2250- 2100 cm-1 is triple-bond stretching , region 2000- 1500 cm-1 is double bonds and the region below 1500 cm-1 is the fingerprint region where a variety of single bonds are absorbed.3 The chromic acid test is a test for oxidizability and gives a positive result for primary and secondary alcohols as well as aldehydes2. A positive result in the chromic acid test is indicated by a color change and the formation of a precipitate. Tertiary alcohols give negative results for the chromic acid test since there must be a hydrogen present on the alcoholic carbon for oxidation to occur. The 2,4 DNP test, tests for a carbonyl and is therefore a dependable test for aldehydes and ketones. Finally, 13C NMR spectroscopy is a test to determine the structure of a compound. 13C NMR detects the 13C isotope of carbon. Each carbon has a different chemical shift. A carbon’s chemical shift is affected by the electronegativity of nearby atoms. Carbons that are bonded to highly electronegative atoms resonant downfield because the electronegative atom pulls electrons away from the nearby carbons and cause those carbons to resonant downfield1 (John McMurry, 2008). A general trend is that sp3-hybridized carbons absorb from 0 to 90 ppm, sp2-hybridized carbons resonant between 110
The light yellow precipitate was collected by suction filtration using a Hirsch funnel. The product was washed with two 1-mL portions of cold methanol followed by two 1-mL portions of diethyl ether. The product was dried in the oven at 110°C. The IR spectrum as a KBr pellet was obtained for the product and inosine for analysis.
Before any calculations, the spectra from the HCl solution and NaOH solution was verified to make sure that the wavelength at which the deprotonated form of 2-naphthol absorbs at 345 nm and that protonated form does not absorb significantly at the same wavelength. All the spectra in Figure 1 were baseline-corrected using the HCl solution spectrum, shown in Figure 2, and the NaOH solution spectrum was used to determine Amax at 345 nm.
In order to synthesize our metal complexes, we were able to make both Copper and Ruthenium metals. From this, we combined each metal complex with DMSO by refluxing the compound. The metal complexes were analyzed through their melting point and IR spectroscopy to determine whether the metal bonded to a Sulfur atom or an Oxygen atom of the DMSO. After analyzing the IR spectrum, it was determined that S=O shifted to a lower wavenumber in CuCl2~2DMSO and that S=O shifted to a higher wavenumber in RuCl2~4DMSO.
2. Miller, F.; Wilkins, C. Infrared Spectra and Characteristic Frequencies of Inorganic Ions. Ph.D. Dissertation, Mellon Institute, Pittsburgh, PA, 1952.
This experiment was done to identify one ketone with Thin Layer Chromatography and one using nuclear magnetic resonance spectrometry. When using Thin Layer Chromatography, I was able to determine my unknown by observing my slides and seeing that the spots of my unknown are most like those of 2-heptanone in height and size. Furthermore, I calculated my Rf values and determined that my Rf value of Unknown K (.5) was most near my Rf value of 2-heptanone (.51). Finally, comparing the derivative melting points of these two substances confirms that 2-heptanone is my unknown. The derivative melting point of 2-heptanone is 89 while my unknown was 87.
To characterize the synthesized product using its boiling point, results of simple chemical tests and derivatization reactions, along with the determination of the melting points of the hydrazones and comparison of the hydrazones using their RGB values.