Polymorphic complexes, luminescence

Bi, W.-Y, Lii, X.-Q., Chai, W.-L., etal. (2008) Synthesis, structure and near-infrared (NIR) luminescence of three solvent-induced pseudo-polymorphic complexes from a bimetallic Zn-Nd Schiff-base molecular rmit. Inorganic Chemical Communications, 11, 1316. 

Thus, pure samples of the complex formed crystals with varying luminescence. Most of the crystals exhibited the described yellow luminescence, but others displayed a bluish-white luminescence and a few of the crystals showed a pink luminescence. The two new forms of trinudear complex can be obtained by evaporation of dichloromethane solutions of the complex. They consisted of one triclinic form and one monoclinic form and both crystallized as colorless blocks, in contrast to the results with the original solvoluminescent hexagonal form that crystallized as colorless needles. These polymorphs differed in the packing of the nearly planar molecules and in the nature of the aurophilic interactions between the trinudear units (see Figure 6.16). 

Two polymorphs of the salt [(C6HnNC)2AuI](PF6) have been found [38]. One of these is a yellow solid which displays a greenish emission, while the other forms colorless crystals that produce blue luminescence. Since both forms can be crystallized from a single solution, for example by adding diethyl ether to a dichloromethane solution of the complex, these are known as concomi-... 

The first chapter of this volume by Balch discussed the current progress in two-coordinate luminescent gold(I) complexes. This class of complexes is well-known to show weak metal- metal interactions that lead to the isolation of novel architectures and polymorphism from relatively simple building blocks and the appearance of unique electronic absorption and emission spectroscopic features. The effect of the environment, such as solvents and counter ions, on the luminescence behavior of a number of two-coordinate gold(I) complexes was discussed. 

The concept of the multi-component molecular solid covers co-crystals, mixed crystals, salts, clathrates, and complexes. As Yan and Evans have indicated,multi-component systems of luminescent dyes with a variety of co-assembled units offer a more flexible method for tuning the packing-directed luminescent properties of the dye than the formation of polymorphs of the pure material. An example has already been given above (16). ° Another example is the organic salts of anthracene-2,6-disulfonic acid (20) with amines (Scheme 6). ... 

Besides the platinum and palladium diphosphine systems, platinum polypyridine complexes have also attracted attention in recent years [130-162). Their changes in spectroscopic and luminescence properties brought about by Pt Pt and n-n interactions are of particular interest [138-142). For instance, the square planar platinum(ii) diimine complex [Pt(bpy)Cl2) exhibits polymorphic behavior and rich photophysical properties [142-144). These, together with the recent growing development of platinum alkynyl systems [98, 122, 125, 145-147), mainly due to the... 

Aurophilic interactions in cationic gold complexes with two lisocyanide ligands. Polymorphic yellow and colorless forms of [(cyclohexyl isocyanide)2Au ](PF6) with distinct luminescence, R. L. White-Morris,... 

A reversible polymorphic phase change which affects the luminescence and aurophilic interactions in the gold(I) cluster complex, [jt3-S(AuCNC7H,3)3](SbF5), E. M. Gussenhoven, J. C. Fettinger, D. M. Pham, M. M. Malwitz, A. L. Balch, J. Am. Chem. Soc. 2005,127,10838. 

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