Chemistry is a subject experiencing very rapid growth. New areas of researeh are opened and new methods are developed with a speed whieh must seem impressive. The pieture has, however, another side represented by the great number of unsolved or poorly solved problems left behind when a branch of chemistry is no longer fashionable. When three years ago I beg;m to plan this book I felt that the molecular adduets of oxo compounos constituted just sueh a field of research, and that they might acquire greater interest if approached from the standpoint of modern chemistry. The developments of the last three years have been such, however, that it can no longer be said that interest is lacking. From that point of vic~w a book on this subject may now seem unnecessary. On the other hand individual contributions to this field have been very scattered, and the essential problems have not always been recognized. It is hoped therefore tlat this book will help to coordinate work on these compounds and that future investigations will derive some benefit as a result. For this purpose a systematie treatment is needed and the first and larger part of the book is an attempt to present a fairly complete review of past experimental work. The treatment is not detailed; it is aimed instead at giving the reader a chance to find all the pertinent references.

1. Introduction

2. Conditions for adduct molecule formation
3. Characteristic coordination numbers
4. Structural evidence concerning donor molecules
5. Adducts with donor molecules containing the group C=O
6. Adducts with acyl halides
7. Adducts with donor molecules containing the group ? NO
8. Adducts with donor molecules containing the group - NO2
9. Adducts with donor molecules containing the group - N=O
10. Adducts with donor molecules containing the group ? P=O
11. Adducts with donor molecules containing the group ? As=O
12. Adducts with donor molecules containing the group ? Sb=O
13. Adducts with donor molecules containing the group S=O
14. Adducts with donor molecules containing the group SOO
15. Adducts with sulfur dioxide and sulfur trioxide
16. Adducts with donor molecules containing the Se=O group
17. Adducts with Brönsted acids
18. Ternary adducts with carboxylic acids
19. Other ternary adducts
20. Adduct molecules in the liquid state and in solution
21 Affinity studies
22. Structural data
23. Charge distribution
24. Decomposition of adduct molecules
25. The catalytical activity of acceptor molecules
26. A theory for donor-acceptor interaction with oxo-compounds
27. References.