Bridging bidentate anions

The nature of coordination of anions such as nitrate, perchlorate, and thiocyanate has been studied by both infrared and Raman techniques. In the case of anions, such as nitrate and perchlorate, the vibrational spectra indicate whether they are ionic or coordinated and if coordinated, whether they are unidentate, bidentate or bridging. In the case of thiocyanate, the vibrational spectra are useful in deciding the site of coordination. The change in the site symmetry of the anion upon coordination leads to changes in vibrational spectra of anions like perchlorate, nitrate, perrhenate and hexa-fluorophosphate. These changes in the vibrational spectra have been used to indicate the nature of coordination. 

Iron(II) chloranilate trihydrate contains zigzag chains in which bidentate chloranilate anions bridge octahedral iron centers, each of which has two cis water ligands. Iron(III) chloranilate is dinuclear, with one chloranilate bridge. " ... 

Bis-aquo complexes were also reported with amino acids such as a- and jS-alanine (MeCH(NH2)C02H, CH2(NH2)CH2C02H) and o -aminobutyric acid, EtCHfNH OjH-2558 The anhydrous complexes [NiLj (L = glycinate, alaninate, carboxylate groups both bidentate and bridging.2558,2559... 

Trialkyltin compounds of the type R3SnX, of which the best studied are the CH3 compounds (X = C104, F, N03, etc.), are of interest in that they are always associated in the solid by anion bridging (8-XI and 8-XII) the coordination of the tin atom is close to tbp with planar SnMe3 groups. When X is RC02 the compounds may in addition be mononuclear with unidentate or bidentate carboxylate groups. 

Bridging Bidentate Anions. In the chemistry of binuclear, metal—metal bonded compounds, ligands of the generic type 9-XXIV play a major role because of their relatively high basicity and their ability to hold the metal atoms in close proximity. Actual examples are ... 

We have seen that ions XO3 cannot balance the e.b.s. of an 8-coordinated ion M without rearranging the anionic charge and behaving as either bidentate or bridging ligands. For an ion such as SO4 the possible types of behaviour are more numerous and are rather completely illustrated by the structures of Zr(S04)2 and its hydrates. This compound has an unexpectedly complex structural chemistry, for... 

Rhodium)-1) complexes, 904, 905 Rhodium(O) complexes, 905, 906 triphenylphosphine, 905 Rhodium(l) complexes, 906-929 anionic, 906 bidentate anions At-methylsalicylaldiminato, 908 pentane-2,4-dionato, 908 trifluoroacetato. 908 bridged, 908-911 dinitrogen, 919 binuclear, 920 four-coordinate anions, 925 hydrido, 921 hydrido dinitrogen, 920 pen tacoordin ate anions, 929... 

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