On the interrelationship of mu-OH bridged dimers, trimers, and tetramers of (en)PtII and their Ag+ adducts.
[(en)Pt(mu-OH)2Pt(en)]2+, a dinuclear mu-hydroxo bridged complex (with en = ethylenediamine) crystallizes with excess AgNO3 in high yield as the trinuclear complex [((en)Pt(mu-OH)2Pt(en))Ag](NO3)3 (Pt2Ag, 1) from water. The two halves of the complex are significantly bent (dihedral angle 42.2 degrees ) and the three metals form a triangle with the following distances: Pt1...Pt2, 2.9729(9) angstroms, Pt1...Ag1, 2.818(1) angstroms and Pt2...Ag1, 2.809(1) angstroms. The shortness of the Pt...Ag distances and the dispositions of the three metal ions strongly suggest that dative bonds from Pt to Ag are responsible for the bending of the two halves of the edge-sharing dinuclear [(en)Pt(mu-OH)2Pt(en)]2+ complex. This scenario appears to be yet another cause of bending of edge-sharing dinuclear mu-OH bridged metal complexes of d8 metal ions, adding to those involving Pt...Pt bonding, or anion binding, among others. Comparison with related mu-OH dimers of cis-(NH3)2PtII or (tmeda)PtII (tmeda = N,N,N',N'-tetramethylethylenediamine), which do not display Ag+ binding, suggests that the feature of Ag+ binding is not common to all cis-bis(am(m)ine) complexes of PtII. Interestingly the complete removal of Ag+ from 1 does not lead to the mu-OH dimer but rather to the known mu-OH tetramer [((en)Pt(mu-OH))4]4+.
Shen
Wei-Zheng
WZ
Fakultät Chemie, Technische Universität Dortmund, 44221 Dortmund, Germany.
Schnebeck
Ralf-Dieter
RD
Freisinger
Eva
E
Lippert
Bernhard
B
D018360:Crystallography, X-Ray; D019281:Dimerization; D005029:Ethylenediamines / Q000737:chemistry*; D006878:Hydroxides / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D009944:Organoplatinum Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*
D005029:Ethylenediamines; D006878:Hydroxides; D009942:Organometallic Compounds; D009944:Organoplatinum Compounds; D012834:Silver; C031234:ethylenediamine; C031356:hydroxide ion