Chemistry 401

Intermediate Inorganic Chemistry

University of Rhode Island

Final Exam

December 18, 2001
open notes, open book

All references are to articles from Inorganic Chemistry, 2001, 40.

1. J. F. Lehmann, D. A. Dixon, and G. J. Schrobilgen (pages 3002-3017) prepared some compounds of Kr. Write the Lewis Dot structure, predict the molecular geometry, give the sigma hybridization, and indicate the point group for KrF2, Kr2F3+, and each ion in [KrF][AsF6].

Answer

2. R. Boca, M. Boca, L. Dihán, K. Falk, H. Fuess, W. Haase, R. Jarosciak, B. Papánková, F. Renz, M. Vrbová, and R. Werner (pages 3025-3033) studied the high-spin to low-spin transition in [Fe(bzimpy)2](ClO4)2·0.25H2O [bzimpz = 2,6-bis(benzimidazol-2-yl)pyridine)]. Find the LFSE for each spin state. Is either spin state likely to be Jahn-Teller active?

Answer

3. B. Hoge, C. Thösen, and I. Pantenburg (pages 3084-3088) investigated the acid base reaction between HP(CF3)2 and Hg(CN)2 in the presence of dppe (Ph2PCH2CH2PPh2, Ph = phenyl). Write the acid base reaction (one of the products is [Hg{P(CF3)2}2dppe]). Why is HP(CF3)2 acidic? The role of the dppe is to stabilize the mercury complex. Explain how this may occur.

Answer

4. X.-D. Jiao, P. D. Metelski, and J. H. Espenson (pages 3228-3233) looked at oxidation/reduction reactions between metal acetates and bromide ion. Balance the following reaction:

Co(CH3CO2)3(aq) + HBr(aq) → CoBr2(aq) + CH3CO2H(aq) + Br2(l)

Answer

5. B. Kiran, A. K. Phukan, and E. D. Jemmis (pages 3615-3618) ask the question: is borazine aromatic? Borazine has the formula B3N3. Write the Lewis dot structure, give the point group, and give your opinion about the aromaticity in borazine. Defend your arguments.

Answer

6. G. V. Vajenine, G. Auffermann, Y. Prots, W. Schnelle, R. K. Kremer, A. Simon, and R. Kniep (pages 4866-4870) synthesized BaN2. Estimate the lattice energy of this compound using the Kapustinskii equation (page 57 in your text). You will need to estimate the ionic radius of the anion. To do this, assume a six-coordinate environment and estimate the ionic radius based on similar ions. Then estimate the heat of formation for BaN2 using the lattice energy you calculated. The sublimation energy for Ba(s) is 180.0 kJ/mol and all of the other data required is in your textbook. Based on the heat of formation, do you think the authors had an easy synthesis?

Answer

7. A. S. DelNegro, S. M. Woessner, B. P. Sullivan, D. M. Dattelbaum, and J. R. Schoonover (pages 5056-5057) investigated the photochemical reactivity of [(CO)3(bpy)Re(dppene)Re(bpy)(CO)3]2+ (dppene = trans-Ph2PCH=CHPPh2, Ph = phenyl, and has a systematic name of (E)-1,2-bis(diphenylphosphino)ethylene). Draw the structure of the complex, name the ion, and find the electron count around each Re atom. Do you expect the ion to be stable? Why or why not?

Answer

8. R. Kempe, E. Kessenich, and A. Schulz (pages 5182-5187) studied the Lewis acid-base reaction between (CH3)3SiNPPh3 (Ph = phenyl) and ICN. Identify the Lewis acid, the Lewis base, and write the structure of the product. Comment on the relative stability of the product.

Answer