课程名称︰无机化学二 课程性质︰必修 课程教师︰彭旭明 开课学院：理学院 开课系所︰化学系 考试日期（年月日）︰2011/6/22 考试时限（分钟）：120 是否需发放奖励金：是 （如未明确表示，则不予发放） 试题 : Organometallic Chemistry Part A 1.On the basis of the 18-electron rule, identify the first-row transition metal for each of the following: (a){M(CO)7}+ (b)(OC)5M=C-OCH3 \C6H5 Determine the metal-metal bond order consistent with the 18-electron rule for the following: (c){(n5-C5H5)Fe(CO)2}2 Identify the most likely second-row transition metal for each of the following (d){M(PF3)2(NO)2}+ (contains linear M-N-O) Determine the unknown quantity Z: (e) {(CO)3Ni-Co(CO)3}z (5%) 2. For the hypothetical molecule (n4-C4H4)Mo(CO)4:(15%) (a)Assuming C4V geometry, predict the number of infrared-active C-) bands. (b)SKetch the pi molecular orbitals of cyclobutadiene. For each,indicate which s, p, and d orbitals of Mo are of suitable symmetry for interaction. (Hint: Assign the z axis to be collinear with the C4 axis.) C4v E 2C4 C2 2sigmaV 2sigmaD A1 1 1 1 1 1 z X^2+Y^2, Z^2 A2 1 1 1 -1 -1 Rz B1 1 -1 1 1 -1 x^2-y^2 B2 1 -1 1 -1 1 xy E 2 0 -2 0 0 (x,y)(Rx,Ry) (xz,yz) 3. Reaction of Ir complex A with C60 gave a black solid residue B with the following spectral characteristic: mass spectrum:M+=1056; 1H NMR: delta 7.65 ppm (multiplet, 2H), 7.48 (multiplet, 2H) 6.89 (triplet, 1H) , and 5.97 (doublet, 2H); IR: v(CO)=1998 cm-1 ; Atwt Ir :192 (8%) (a) Propose a structure for B. (b) The carbonyl stretch of A was reported at 1954 cm-1. How does the electron density at Ir change in going from A to B? (c) When B was treated with PPh3, a new complex C formed rapidly, along with some C60. What is a likely structure of C? 4. Predict the products of the following reactions:(8%) (a)W(CO)5{C(C5H5)(OC2H5)} + BF3 >>>>>>> (b){Mn(CO)5}- + H2C-CH-CH2Cl >>>>>>>> intitail product >>>>> final product -CO (c)trans-Ir(CO)Cl(PPh)2 + CH3I >>>>>>>>> (d)Ir(PPh3)3Cl >>>>>> heat 5. Write the catalytic cycle of olefin hydrogenation using Wilkinson's catalyst, {ClRh(PPh3)3} and specify the steps of oxidative addition, ligand dissociation, ligand association, 1,2-insertion and reductive elimination. (10%) 6. Give structural formulas for A through D: {(n5-C5H5)Fe(CO)2}2 >>>> A >>>>> B >>>>>> C >>>>>>>A+D (a hydrocarbon) Na/Hg Br-Br LiAlH4 PhNa Vco=1961, 1942, 1790 cm-1 for {n5-C5H5)Fe(CO)2}2 A has strong IR bands at 1880 and 1830 cm-1 ; C has a 1H NMR spectrum consisting of two singlets of relative intensity 1 : 5 at approximately delta -12 ppm and 5 ppm, respectively. (Hint: Metal hydrides often have protons with negative chemical shifts.) (8%) 7. Predict the products if the following compounds undergo metathesis and give the possible catalyst for methesis: (8%) (a) cyclooctene + butene >>>> (b) cyclopentene + C2H5-=-CH3 (c) 1-butene + 2-butne 8. Propose organic fragments that are isolobal with (a){Re(CO)4}- (b){Co(CN)5}3- (c){Mn(CO)5}+ propose two organometallic fragments that are isolobal with (d)CH3 (e)CH 9. Classify the following as closo, nido, or arachno:(a)C2B3H7 (b)B6H12 (c) B11H112- (d) C3B5H7 (e) ZB10H142- (5%) 10.Draw the structure of B6H62- and draw the three-center bonds in B6H62- using valence bond theory. How many boron three center bonds and boron two center bonds are in the B6H62-?(5%) 11.THe maximum bond order for a diatomic chemical species has been calculated to be six, for example in Cr2. What types of orbital interactions would be possible in this molecule? Calculate and display the molecular orbitals for Cr2, and classify them as sigma, pi, or delta and as bonding or antibonding. Identify the atomic orbitals used in each molecular orbital. Are your results consistent with a bond order of six?(8%) Bioinorganic CHemistry Part B 1. (12pt) From the following figures of metalloprotein active sites, CHOOSE FOUR out of SIX to answer: a. Identify the name of the protein/enzyme (write the full name) b.Write the reaction(s) that the active site may be involved(write balanced equations) 2.(5pt)THe following graph is a O2 saturation-dissociation curve of adult hemoglobin (solid line). a.What is meant by the term 'P1/2' (or'P50')? What is the value for P1/2 on this curve (solid line)? b. The curve can be shifted to left or to right(e.g broken lines). indicate whether you expect a left or right shift by and increase of the following factors:(1)lactic acid and (3)concentration of CO2. C In the presence of carbon monoxide(CO), a left shift is observed. Explain what is happening. 3(8pt)CHoose the correct answer for the following questions (图略) a. Which of the following imidazole proton is a better acid? b.WHich of the following shows the correct direction of the reaction? This process forms the basis for redow-coupled proton-pumping. c.Which copper complex has a lower E1/2(harder to deduce)? d. Which of the following compounds should give a most stable dioxygen adduct? 4. (5pt) Indicate the spin number of the following complexes. 5. (8 pt) on the 'ferryl' (compound I) reactive species of cytochrome P-450 a. Draw the Lewis structure of the possible valence tauomers of the formally Fe(V)=O porphyrin, with and without the thiolate ligand. One structure of each is already drawn; you complete the others. b.Disscuss at least 3 methods by which the Fe(V)=O species can be generated (in enzyme and in models). c. The data below give the % yields of observed products in the monooxygenation of cyclohexebe using different porphyrin Mn(III)Cl catalysts. Discuss any trends you observe, the reasons behind the trend, and your conclusion. 6.(3 pt) Infrared spectra of MnII(TPP) and O2 complexses at about 15k are shown below. The three dioxygen isotopes (16O2, 16O18O and 18O2) give the o-o stretching frequency at 983, 958, and 933 cm-1, respectively. TPP=tetraphenylporphyrin. What is the most lilely structure of the Mn-O2 complex (superoxide? n1-mode ?) 7. (4pt) The following is the EPR spectra of coenzyme B12, using different labeled imidazoles. {59Co has I=7/2; 14N, I=1; 15N, I=1/2} Focus on the region of 300-370 mT, (a) indicate on both spectra the hyperfine lines and the superhyperfine lines. (b)Based on your analysis, draw an arrow to show the position of the g-value(this would be g||). --

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