title: Half-sandwich complexes of iridium and ruthenium containing cysteine-derived ligands.
abstract: The dimers [{(ηn-ring)MCl}2(μ-Cl)2] ((ηn-ring)M = (η5-C5Me5)Ir, (η6-p-MeC6H4iPr)Ru) react with the modified cysteines S-benzyl-l-cysteine (HL1) or S-benzyl-α-methyl-l-cysteine (HL2) affording cationic complexes of the formula [(ηn-ring)MCl(κ2N,S-HL)]Cl (1, 2) in good yield. Addition of NaHCO3to complexes 1 and 2 gave equilibrium mixtures of neutral [(ηn-ring)MCl(κ2N,O-L)] (3, 4) and cationic [(ηn-ring)M(κ3N,O,S-L)]Cl (6Cl, 7Cl) complexes. Similar mixtures were obtained in one-pot reaction by successive addition of the modified cysteine and NaHCO3to the above formulated dimers. Addition of the N-Boc substituted cysteine derivative S-benzyl-N-Boc-l-cysteine (HL3) and NaHCO3to the dimers [{(ηn-ring)MCl}2(μ-Cl)2] affords the neutral compounds [(ηn-ring)MCl(κ2O,S-L3)] ((ηn-ring)M = (η5-C5Me5)Ir (5a), (η6-p-MeC6H4iPr)Ru (5b)). Complexes of the formula [(ηn-ring)MCl(κ3N,O,S-L)][SbF6] (6Sb-8Sb), in which the cysteine derivative acts as a tridentate chelate ligand, can be prepared by adding one equivalent of AgSbF6to the solutions of compounds 5 or to the mixtures of complexes 3/6Cl and 4/7Cl. The amide proton of compounds 8aSb and 8bSb can be removed by addition of NaHCO3affording the neutral complexes [(ηn-ring)M(κ3N,O,S-L3-H)] ((ηn-ring)M = (η5-C5Me5)Ir (9a), (η6-p-MeC6H4iPr)Ru (9b)). Complexes 9a and 9b can also be prepared by reacting the dimers [{(ηn-ring)MCl}2(μ-Cl)2] with HL3 and two equivalents of NaHCO3. The absolute configuration of the complexes has been established by spectroscopic and diffractometric means including the crystal structure determination of (RIr,RC,RS)-[(η5-C5Me5)Ir(κ3N,O,S-L1)][SbF6] (6aSb). The thermodynamic parameters associated with the epimerization at sulphur that the iridium compound [(η5-C5Me5)Ir(κ3N,O,S-L3-H)] (9a) undergoes have been determined through variable temperature1H NMR studies.
authors.affiliation: Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Departamento de Química Inorgánica, Pedro Cerbuna 12, 50009 Zaragoza, Spain. dcarmona@unizar.es riromar@unizar.es.
authors.forename: María
authors.initials: M
authors.lastname: Carmona
authors.affiliation: Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Departamento de Química Inorgánica, Pedro Cerbuna 12, 50009 Zaragoza, Spain. dcarmona@unizar.es riromar@unizar.es.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Rodríguez
authors.affiliation: Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Departamento de Química Inorgánica, Pedro Cerbuna 12, 50009 Zaragoza, Spain. dcarmona@unizar.es riromar@unizar.es.
authors.forename: Fernando J
authors.identifier: http://orcid.org/0000-0001-8054-2237
authors.initials: FJ
authors.lastname: Lahoz
authors.affiliation: Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Departamento de Química Inorgánica, Pedro Cerbuna 12, 50009 Zaragoza, Spain. dcarmona@unizar.es riromar@unizar.es.
authors.forename: Pilar
authors.initials: P
authors.lastname: García-Orduña
authors.affiliation: Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Departamento de Química Orgánica, Pedro Cerbuna 12, 50009 Zaragoza, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Cativiela
authors.affiliation: Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Departamento de Química Inorgánica, Pedro Cerbuna 12, 50009 Zaragoza, Spain. dcarmona@unizar.es riromar@unizar.es.
authors.forename: José A
authors.initials: JA
authors.lastname: López
authors.affiliation: Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Departamento de Química Inorgánica, Pedro Cerbuna 12, 50009 Zaragoza, Spain. dcarmona@unizar.es riromar@unizar.es.
authors.forename: Daniel
authors.identifier: http://orcid.org/0000-0003-4196-5856
authors.initials: D
authors.lastname: Carmona
mesh_terms: D003545:Cysteine / Q000737:chemistry*; D007495:Iridium / Q000737:chemistry*; D008024:Ligands; D009942:Organometallic Compounds / Q000737:chemistry*; D012428:Ruthenium / Q000737:chemistry*
chemical_list: D008024:Ligands; D009942:Organometallic Compounds; D007495:Iridium; D012428:Ruthenium; D003545:Cysteine