Intramolecular forces interactions that occur

More complicated cross-terms between the different intramolecular degrees of freedom are also employed in some force fields, but we will not consider them in the following. The dihedral term may also include four-center improper torsion or out-of-plane bending interactions that occur at sp2 hybridized centers.29... 

A dinuclear cyclometalated platinum(II) complex [Pt2L2 (dppm)] + (L = 4-(jo-diethylphosphonophenyl)-6-phenyl-2, 2 -bipyridine) has been employed as a luminescent probe for SDS micelles. Addition of SDS micelles to an aqueous solution of the complex led to an entission band at 530 mn, which was similar to the MLCT emission of mononuclear species. The observations were attributed to the absence of intramolecular and/or intermolecular Pt(II) Pt(II) interactions when the complex was incorporated in the SDS nticelles. Addition of NaCl solution into a micellar solution of the complex resulted in an additional MMLCT ((da )— (tt )) emission band at 650 nm. It was suggested that addition of sodium cations would force two cyclometalated platinum(II) units sufficiently close for intramolecular metal-metal and/or ligand-ligand interactions to occur, and thus the observation of MMLCT luminescence. 

Recall that atoms can form stable units called molecules by sharing electrons. This is called intramolecular (within the molecule) bonding. In this chapter we will consider the properties of the condensed states of matter (liquids and solids) and the forces that cause the aggregation of the components of a substance to form a liquid or a solid. These forces may involve covalent or ionic bonding, or they may involve weaker interactions usually called intermolecular forces (because they occur between, rather than within, molecules). 

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