Diamagnetism underlying

Bis(2,2,6,6-tetramethyl-3,5-heptanedionato)nickel(II) was found to be diamagnetic under all conditions presumably due to steric interactions of the bulky tertiary butyl groups. 

The two primary causes of shielding by electrons are diamagnetism and temperature-independent paramagnetism (TIP). Diamagnetism arises from the slight unpairing of electron orbits under the influence of the magnetic field. This always occurs so as to oppose the field and was first analysed by Lamb [7]. A simplified version of his fomuila. 

AuFj is an unstable, polymeric, diamagnetic, dark-red powder, produced by heating [02][Aup6] under reduced pressure and condensing the product on to a cold finger ... 

Values of the diamagnetic anisotropy of benzene and other aromatic hydrocarbon molecules are calculated on the basis of the assumption that the p, electrons (one per aromatic carbon atom) are free to move from carbon atom to adjacent carbon atom under the influence of the impressed fields. When combined with the assumed values for the contributions of the other electrons (-2.0X 10-6 for hydrogen, —4.5 X10 c for aromatic carbon, — 6.0XlO-6 for aliphatic carbon) these lead to principal diamagnetic susceptibilities of molecules in approximate agreement with the available experimental data. The diamagnetic anisotropy of graphite is also discussed. 

Yamagishi, A., Takeuchi, T., Higashi, T. and Date, M. (1989) Diamagnetic orientation of polymerized molecules under high magnetic field. J. Phys. Soc. Jpn., 58, 2280-2283. 

Reactivity of compounds 1 and 2c with O2 is remarkably different from that of 5c, 5cCo, and 8 (Fig. 18.18). Metalloporphyrin 2c binds O2 reversibly at room temperature under anhydrous conditions to produce a diamagnetic ferric-superoxo/Cu adduct as demonstrated by resonance Raman spectroscopy using 2 and 2... 

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