Exchange experiments/spectroscopy basics

Other basic 2-D experiments include J spectroscopy, which displays scalar-coupled multiplets along the second dimension, and nuclear Overhauser effect spectroscopy (NOESY, pronounced nosy ), which exploits through-space dipolar couplings to provide conformational information. In the NOESY experiment, protons are selectively irradiated as data are acquired, and the effect of neighboring nuclei is monitored by their mutual enhancement. NOESY is one example of an exchange experiment, in which magnetization is transferred from spin to spin. 

Kawi et al. [4, 60] reported on experiments comparing the iridium carbonyl chemistry in NaY zeolite with that in the more basic NaX zeolite (some of whose basicity should perhaps be attributed to the excess NaOH used in the preparation which was ultimately not washed out). The results showed that the supercages in the NaX zeolite were sufficiently basic to provide an effident medium for the synthesis of anionic iridium carbonyl clusters. When [Ir(CO)2(acac)] in NaX zeolite was treated with CO, it was transformed into [HIr4(CO)n] and then into [Irg(CO)t5]. The anionic carbonyl dusters trapped in the cages were characterized by infrared and EXAFS spectroscopies and could not be extracted from the zeolite by ion exchange with bis(triphenylphosphine)iminium chloride, [PPN][Q], in tetrahydrofuran solution. 

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