Inner complexes

Salt Formation and Metal Chelation, Most a-ainiao acids form salts in alkaline and acidic aqueous solutions (88). For example, a-amino acids form inner complex salts with copper. 

In chelation complexes (sometimes called inner complexes when uncharged) the central metal ion coordinates with a polyfunctional organic base to form a stable ring compound, e.g. copper(II) acetylacetonate or iron(III) cupferrate ... 

Called an outer complex by the original workers, the meaning of the term outer being unspecified. Subsequent workers in this field have all argued that outer complexes are merely -complexes. Likewise, the cr-complexes were referred to originally as inner complexes. 

Mulliken [3] presented a classification of electron donor-acceptor complexes based on the extent of intermolecular charge transfer that accompanies complex formation. An outer complex is one in which the intermolecular interaction B- XY is weak and there is little intra- or intermolecular electric charge redistribution, while an inner complex is one in which there is extensive electric charge (electrons or nuclei) redistribution to give [BX] + - -Y . Inner complexes are presumably more strongly bound in general than outer complexes. 

Nebenvalenz) to describe the chemical forces underlying formation of inner complexes, and G. N. Lewis s general concept of the Lewis-acid-base adduct allowed many types of coordinate bonding to be recognized as simple extensions of Lewis-like covalent concepts. 

The investigations, which aimed to establish the character of the interaction as either ion-pair like (outer complex) or H-bonded-like (inner complex), started with the first... 

The coordination process may either stabilize or destabilize aromatic Schiff bases. If nickel (II) salts are added to ammoniacal solutions of salicylaldehyde, the precipitate obtained is the inner complex salt of nickel (II) and salicylaldimine (61). If beryllium chloride is added to the Schiff base derived from 2-hydroxy-l-naphthaldehyde and ethylamine, however, the Schiff base is decomposed and the inner complex of beryllium (II) and 2-hydroxy-1-naphthaldehyde is obtained (59). Here the strength of the coordinate bonds formed with the metal seems to determine which complex will be formed. 

TWENTIETH-CENTURY DEVELOPMENTS 1.1.5.1 Inner Complexes Ley and Bruni (1904)... 

Werner s coordination theory25 was a watershed in the history of coordination chemistry and gave the field its name. With a few exceptions, the majority of chemists accepted Werner s views, and most 20th century contributions have been developments, extensions or confirmations of Werner s theory rather than ideas incompatible with or opposed to it. Ley s concept of inner complex salts is one of the earliest of such post-Werner developments.80... 

Like ihe neighboring elements of group 8, iron forms large numbers of complexes. This is due to ihe availability of two d orbitals in Fe2+ and Fe3+ to form hybrid orbitals with the 4s and 4p orbitals to yield spin-paired complexes (the so called "covalent or inner-- complexes). 

Soon after the introduction of dimethylglyoxime as a specific reagent for nickel by Tschugaeff-Kraut-Brunck (1905-1907), Baudisch discovered a compound which precipitates copper and iron quantitatively from acid solutions.82 He appropriately named this reagent as cupferron . It is the water soluble ammonium salt of nitrosophenylhydroxylamine (5). When dissolved in chloroform, the whitish-grey copper compound gives a bright yellow solution and the brown yellow iron(III) compound a deep red solution. This behaviour reveals the inner complex character of these derivatives (6). 

Truax, 1994] Truax, B. (1994). Discovering inner complexity Time shifting and transposition with a real-time granulation technique. Computer Music J., 18(2) 38-48. 

DPCC are obtained on the basis of metal-containing ligands, which can be classical Werner complexes (Scheme 1.11), salicylaldiminates [140], and other inner-complex compounds, as well as numerous organometallic compounds [112,113,159] ... 

A change of salt anions allows us to carry out controlled syntheses of definite types of coordination compounds. Thus, metal halides are widely used to prepare molecular (Sec. 3.1.1.1) and ti-complexes (Sec. 3.1.1.3). Metal acetates are mostly applied in the syntheses of metal chelates and, especially, inner-complex compounds (Sec. 3.1.1.2). Di- and polynuclear structures are formed under use of the anions mentioned above, which, in some cases, determine (see Sec. 3.1.1.4) a type and donor centers of bridge fragments. At the same time, the mentioned approach to choice of salts of metal complex-formers has many exceptions, although it is useful. 

Additionally to the indicated chelates, other inner-complex compounds, for example those on the basis of hetarylformazanes (3.206) [448], can also take part in the examined template transformations ... 

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