Inorganic Chemistry
Questions & Answers
QUESTION 3: In question 2 you worked with octahedral complex anions of [VCl₂(O₂CCO₂)₂]³ in this question you are asked to consider trigonal prismatic [VCl₂(0₂CCO2)2]³ complex anions. a) Draw 2 distinguishable isomers of the [VCl₂(O₂CCO2)2]³ complex with trigonal prismatic geometry and determine their point groups. You must use dashes and wedges correctly. Indicate all atoms including the ligand atoms. i. Isomer 3 (trigonal prismatic): 3-dimensional structure: Point group:
| Rotate the molecule to keep the "linear" arrangement (see below) and set the electronegativities of A, Band C to middle. Click to show the bond dipoles,molecular dipoles and partial charges. Draw the bond dipoles on the bonds in the diagram Show the overall molecular dipole in the diagram Draw the partial charge symbols on the diagram.
This question relates to The role of metal-containing proteins in biological processes and Molecular orbital theory of transition-metal complexes sections. a) Nitro genases catalyse the reduction of dinitrogen to ammoniain bacteria. These enzymes are comprised of a complex oftwo proteins, with the Fe-protein transferring electrons to the FeMo protein, where dinitrogen reduction occurs. The precise mechanism for the reduction of dinitrogen is still poorly understood so the behaviour of other small molecule or ion substrates, such as CO and CN- have been studied to improve understanding. i. The protein consists of four polypeptide chains, with each chain marked by a different colour (when the polymer is shown as a cartoon, as it should be when you enter the page). Take a screen grab of the protein and state which chain corresponds to which colour. You can identify the chains by hovering over them. You may need to rotate the structure to identify all the chains.(2 marks) ii. On the tab on the right-hand side of the page titled"Structure", remove the polymer atoms (the polypeptidechain) from the view by clicking on the dustbin symbol adjacent to the polymer option. Then, screen grab the image and upload to your answer. iii. The structure contains two pairs of clusters. By referring to the information given in the Visualising molecules and proteins document, measure the distance between the metal-sulfur clusters in either of these pairs. Note, you will lneed to select the "Residue" option, rather than the"Atom/coarse element" option described in the visualisation document, from the Residue drop-down menu. This is because the clusters are classed as residues in the PDB. iv. Examine, the metal-sulfur clusters in the protein. Describe how each pair of clusters meets the criteria for a good electron transport system. v. For one of the pair of metal-sulfur clusters, identify whichis the cluster is the P-cluster and which is the FeMo-cofactor and upload an annotated screengrab whichshows your choice. vi. Based on your knowledge of nitrogenases, which of the P-cluster or the FeMo-cofactor would you expect to have thelower electrode potential? Explain your answer. vii. One of the clusters in each pair has CO bound to it.Describe coordination mode of the CO including a sketch of how the CO interacts with the metal atoms (you don't need to include the whole cluster in your sketch).
I need an electron to be traveling at 0.970c. What potential difference should I use to accelerate it, assuming it starts from rest? Recall U=qV.
Click the reset button.Change the arrangement of atoms to a "linear"arrangement (see below) and set the electronegativities of A and C to high and keep B to middle. Click to show the bond dipoles,molecular dipoles and partial charges. Draw the bond dipoles on the bonds in the diagram Show the overall molecular dipole in the diagram Draw the partial charge symbols on the diagram.
3. Which would you expect to have a higher boiling point. A molecule with a large molecular dipole or a molecule with no molecular dipole. Explain your choice
11. Does the molecule 1,3-dichloro-1,2-propadiene have a dipole moment? Draw the molecule and explain.
Tuberculosis is a bacterial disease that causes the deaths of over1 million people a year annually. These bacteria survive within white blood cells and the acquisition of the iron they need for survival can be difficult. The bacteria use two types of siderophore to aid the acquisition of iron. Shown below are compound 4 which is an example of one type and compound 5 is an example of the second type used by these bacteria. a) Based on what you know about siderophores, identify thechelating group present in compound 4. b) Identify the denticity of compound 4 and by considering the most favoured coordination geometry of Fe(lII), state how many molecules of compound 4 are required to fully coordinate one Fe(lll) ion? c) Predict the charge of the complex formed by compound 4and Fe(llI) at pH 7, explaining how you came to your answer. Note, the approximate pK, values for 4 are around 2.5 for-COOH, between 9 and 10 for -NH3* and between 6 and 7for -CON(OH). marks)d) Comment on the significance of each of the following points with respect to compound 4, in terms of its efficacy as a siderophore. i. The stability constant for this ligand with Fe(llI) is 1031.4.You should also suggest whether the value is high or low,and explain why this might be the case. ii. E° (Fe+| Fe2+) for the complex is -0.55 V e) Compound 5 is a membrane bound siderophore and aids transport of the Fe* into the cell, where it is reduced to Fe*.It is believed that siderophore 4 transports iron to siderophore 5 in the bacteria which cause tuberculosis. By considering the structure of compound 5, and the following data, suggest how compound 5 aids transport of iron into the bacterial cell. Stability constant for compound 5 with Fe(III) is 1022.7 E° (Fe*| Fe*) for the complex is -0.30 V.
QUESTION 1: You have prepared for the first time ever the XeCl3FO₂ molecule. Naturally the molecule can only be prepared at very low temperatures and tends to undergo instantaneous decomposition into its elements at elevated temperatures. a) You are storing 2 grams of XeCl3FO₂ in a sealed flask at 111 Kelvin. You decompose XeCI-FO₂ into its elements by raising the temperature in sealed flask to 20°C. (i) Write down the decomposition reaction. (ii) Calculate the minimum volume of this flask (in units of liters) in order to keep the pressure at 20°C below 3 bar.
