title: Mono- and diprotonation of the superbasic bisguanidine 1,2-Bis(N,N,N',N'-tetramethylguanidino)benzene (btmgb) and Pt II and Pt IV complexes of chelating bisguanidines and guanidinates.
abstract: New Pt complexes of chelating bisguanidines and guanidinate ligands were synthesized and characterized. 1,2-Bis(N,N,N',N'-tetramethylguanidino)benzene (btmgb) was used as a neutral chelating bisguanidine ligand, and 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidinate (hpp(-)) as a guanidinate ligand. The salts [btmgbH]+[HOB(C6F5)3](-) and [btmgbH2]Cl2 and the complexes [(btmgb)PtCl2], [(btmgb)PtCl(dmso)]+[PtCl3(dmso)](-), and [(btmgb)PtCl(dmso)]+[Cl(-)] were synthesized and characterized. In the [btmgbH]+ cation the proton is bound to only one N atom. In the other complexes, both imine N atoms are coordinated to the Pt II, thus adopting a eta2-coordinational mode. The hpp(-) anion, which usually prefers a bridging binding mode in dinuclear complexes, is eta2-coordinated in the Pt IV complex [(eta2-hpp)(hppH)PtCl2(N(H)C(O)CH3)], which is formed (in low yield) by reaction between cis-[(hppH)2PtCl2] and H2O2 in CH3CN.
authors.affiliation: Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany.
authors.forename: Anastasia
authors.initials: A
authors.lastname: Peters
authors.forename: Ute
authors.initials: U
authors.lastname: Wild
authors.forename: Olaf
authors.initials: O
authors.lastname: Hübner
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Kaifer
authors.forename: Hans-Jörg
authors.initials: HJ
authors.lastname: Himmel
mesh_terms: D001555:Benzene Derivatives / Q000737:chemistry*; D002412:Cations / Q000737:chemistry; D002614:Chelating Agents / Q000737:chemistry*; D018360:Crystallography, X-Ray; D019791:Guanidine / Q000737:chemistry*; D006146:Guanidines / Q000737:chemistry*; D008024:Ligands; D008958:Models, Molecular; D015394:Molecular Structure; D017671:Platinum Compounds / Q000737:chemistry*; D011522:Protons; D013053:Spectrophotometry
chemical_list: C532388:1,2-bis(N,N,N',N'-tetramethylguanidino)benzene; D001555:Benzene Derivatives; D002412:Cations; D002614:Chelating Agents; D006146:Guanidines; D008024:Ligands; D017671:Platinum Compounds; D011522:Protons; D019791:Guanidine