• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Experiment 12: The Paramagnetic Complex- Mn(acac)3

Extracts from this document...


Experiment 12: The Paramagnetic Complex- Mn(acac)3 Kimberlee London Department of Chemistry, Saint John's University Lab Date: February 1, 2011. Report Due: February 8, 2011. Abstract: The manganese complex [Mn(acac)3] is an octahedral complex containing three bidentate ligands. Because each metal ion carries a +3 charge, and each ligand carries a -1 charge, the complex is electrically neutral. Tris(acetylacetonato)manganese(III) was prepared and used for magnetic susceptibility. The number of unpaired of electrons were determined through this process to assign the geometry and to gain information on the bonding between the ligand and metal. The Tris(acetylacetonato)manganese(III) complex had four unpaired electrons. The ligand was a weak field strength thus concluding in a high spin. Introduction: Magnetic susceptibility is the magnetic moment of an atom or ion due solely on its spin of N unpaired electrons. A substance has the ability to apply its own field within the magnetic balance, which will add (paramagnetic) or subtract (diamagnetic) to the applied field. [4] It is predictable that paramagnetic compounds will have unpaired electrons because they contribute by adding to the magnetic field of the balance by the electron's angular momentum (characterized as high spin). Therefore, diamagnetic compounds will have no unpaired electrons because the entrance to the higher sub-shells is too large for the electrons to overcome (characterized as low spin). ...read more.


I measured 0.76 grams. The balance must be zeroed. The balance was first calibrated. The constant was calculated to 1.0823. The temperature before and after the reading should be noted in order to see if any outside factors would be affecting the balance readings. The temperature remained fairly constant around 21?C. The balance reading for the empty tube, Ro was determined by inserting the tube and recording the out and in recordings. Next the tube was filled with sample of the Tris(acetylacetonato)manganese(III). The sample was transferred using a spatula and by gently tapping the tube against the desk. This was repeated until the height between 2.4-4.5 cm was obtained. The height of my sample was 2.90 cm. The sampled filled tube was weighed in order to determine the weight of the sample in the tube. The weight of the sampled tube was 0.87 grams. My total weight of sample used in the magnetic susceptibility balance was .11 grams. It was important to pack the sample efficiently so that an accurate reading can be taken from the balance. The final reading of the filled sample tube was taken. Also, the actual yield of the Tris(acetylacetonato)manganese(III) was measured to be 6.15 grams Results: Table 1: Data for Calibration (1169 std) ...read more.


Whether a metal has high or low spin depends on how strong the ligands and their splitting with respect to the metal. Ligands, which cause large splitting, ? , of the d- orbitals are referred to the strong field ligands. The spectrochemical series tells us how strong the ligands are with respect to the metal. We get splitting, according to the Crystal Field Theory, CFT. Mn(III) had 4 unpaired electrons. There was a weak field, thus resulting in high spin. Conclusion: The number of unpaired electrons can provide information about the bonding between the metal and the ligand. Determing the number of unpaired electrons is also useful for assigning symmetry. Octahedral ligands have the ability to cause a splitting of the orbitals. The spectrochemical series is a list of ligands that puts them in the order of their ability to cause large orbital separations. For d4 metals, Mn(III), two possible electron separations can occur depending on the gap, the field strength creating low or high spin. If the energy gap is large enough, all the electrons will be placed in the t2g (low-spin). If the energy gap is small, the four electrons will be paired in each orbitals first. Mn(acac)3 is a weak field/ high spin case. It has a configuration of 3 electrons in the t2g orbital and 1 electron in the eg orbital. In total there were 4 unpaired electrons. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our University Degree Chemistry section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related University Degree Chemistry essays

  1. A 0.60 um film of silicon dioxide is to be etched with a buffered ...

    This question has been completed using the same technique that was performed in question 6-2-c. Again, I have completed this question with the assumption that the average slope of the window edge can be determined by drawing a line connecting the window edge at the top of the silicon dioxide film to the window edge at the oxide-substrate interface.

  2. Spectrochemical Series of Some d-block Transition Metal Complexes. The spectrochemical series of the ligands ...

    possible to construct a spectrochemical series that arranges the ligands according to their ability to cause d orbital splitting in a given oxidation state. The spectrochemical series can be summarized as: Based on the trend, the multiply-bonded ligands are stronger than nitrogen donors.

  1. Synthesis of different cobalt compounds through ligand exchange was performed in this laboratory. ...

    By studying the electrical conductance of a particular substance, it is possible to relate that to the number of ions in that substance. Electroconductivies will be found and analyzed for each of the products mentioned. Resistance is the measured quantity of an electroconductor, but the particular machine used for this lab gave conductance readings.

  2. Optimizing a Windows-Based Computer Data Acquisition and Reduction System for the General Chemistry Laboratory

    for grading the laboratory reports. The chemistry department staff decided that there are four components of a complete laboratory report: the Introduction, Data Presentation, Data Analysis, and Conclusion. The Introduction states the purpose, explains the experimental method, identifies relevant chemical and mathematical equations, and places the experiment in context with the chemical program and/or the everyday world.

  1. Forensic Chemistry - Ion Selective Electrode. The objective of experiment is to determine ...

    This means that other ions in solution may also be sensed by an ISE although it is not designed to do so. The ion that is to be determined is referred to as the determinant and other ions to which an electrode responds are known as Interferents or interfering ions.

  2. The objectives of this experiment are to synthesis 1-bromobutane from n-butanol under reflux setup ...

    3.3.4 Next, we have extracted the organic layer again with 15ml of saturated sodium hydrogencarbonate to neutralize and remove the acid into the aqueous phase in the same separatory funnel. Organic Phase (Bottom) Inorganic Phase (Top) Mostly 1-bromobutane H2SO4 + 2 NaHCO3 ï Na2SO4 + 2 CO2 + 2 H2O

  1. The objective of this experiment is to determine how a buffer system resists large ...

    2.3 Instrument- Glass electrodes pH meter Figure 8: Combined pH glass electrode (Laboratory Talk 2009). The most common type of pH electrodes are the "glass" electrodes. They consist of a special glass membrane that is sensitive to variations in pH, as pH variation also changes the electrical potential across the glass.

  2. Steam Distillation of (S)-(+)-Carvone from Caraway Seeds and (R)-(- )-Carvone from Spearmint Leaves. Analysis ...

    The solvent was allowed to travel up the mark that was about 8 cm away from the baseline for both plates. Then, the TLC plates were removed from the beaker. Part IV: Baeyer?s Test A UV light detector was used to determine movement of the compound on TLC plate.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work