http://www.mdpi.com/journal/molecules/special_issues/organometallic-chem/ Dear Colleagues, Organometallic chemistry is a broadly defined area at the intersection of inorganic and organic chemistry. The chemistry of compounds containing metal carbon and metal hydrogen bonds has been extensively explored and continues to dominate much of the research in catalysis. Over the years organometallic complexes and compounds have found tremendous utility in numerous areas including, but not limited to, organic synthesis, catalysis, and medicinal chemistry. The focus of this special issue is to present papers that cover the wide range of organometallic chemistry including: synthesis, structure, and reactivity of compounds containing metal carbon bonds. Organometallic complexes with applications in medicinal chemistry, catalysis, or other synthetically useful transformations will be of particular interest. For the purposes of this special issue any isolable compound, proposed intermediate, or transition state containing a metal or metalloid with a bonding interaction to carbon or hydrogen will be considered "organometallic". Manuscripts "in the spirit" of organometallic chemistry will also be considered. Prof. Dr. Brian J. Frost Guest Editor {snippet name="submission_info"} http://www.mdpi.com/1420-3049/16/8/6215/ The synthesis and structure of palladium complexes of trisubstituted PTA derivatives, PTAR3, are described. Water-soluble phosphine ligands 1,3,5-triaza-7-phosphaadmantane (PTA), tris(aminomethyl)phosphine trihydrobromide, tri(aminomethyl) phosphine, 3,7-dimethyl-1,5,7-triaza-3-phosphabicyclo[3,3,1]nonane (RO-PTA), 3,7-diacetyl-1,3,7-triaza-5-phosphabicyclo[3.3.1]nonane (DAPTA), lithium 1,3,5-triaza-7-phosphaadamantane-6-carboxylate (PTA-CO2Li), 2,4,6-triphenyl-1,3,5-triaza-7-phosphatricyclo [3.3.1.1]decane, and 2,4,6-triphenyl-1,3,5-triaza-7-phosphatricyclo[3.3.1.1]decane were used as ligands for palladium catalyzed Suzuki reactions in aqueous media. RO-PTA in combination with palladium acetate or palladium chloride was the most active catalyst for Suzuki cross coupling of aryl bromides and phenylboronic acid at 80 °C in 1:1 water:acetonitrile. The activity of Pd(II) complexes of RO-PTA is comparable to PPh2(m-C6H4SO3Na) (TPPMS) and P(m-C6H4SO3Na)3 (TPPTS) and less active than tri(4,6-dimethyl-3-sulfonatophenyl)phosphine trisodium salt (TXPTS). Activated, deactivated, and sterically hindered aryl bromides were examined, with yields ranging from 50% to 90% in 6 h with 5% palladium precatalyst loading. X-ray crystal structures of (RO-PTA)PdCl2, (PTAR3)2PdCl2 (R = Ph, p-tert-butylC6H5), and PTAR3 (R = p-tert-butylC6H5) are reported. http://www.mdpi.com/1420-3049/16/8/6215/ Mon, 25 Jul 2011 00:00:00 CEST Molecules 2011-07-25 16 8 Article 6215 6231 1420-3049 The Suzuki Reaction in Aqueous Media Promoted by P, N Ligands 2011-07-25 doi: 10.3390/molecules16086215 Jason A. Weeden Rongcai Huang Kathryn D. Galloway Phillip W. Gingrich Brian J. Frost http://www.mdpi.com/1420-3049/16/7/6082/ Crystals of trans-Pt2(μ-X)2X2(CO)2 (X = Br, I) have been grown and their molecular and crystalline structures have been solved by X-ray diffraction methods. In both cases the dinuclear molecules are bent, with a bending angle of 164.6° and 156.5° for the bromide and the iodide, respectively. While the structure of the bromo-derivative is reported here for the first time, a modification of trans-Pt2(μ-I)2I2(CO)2 with planar centrosymmetric molecules is known. This appears to be a rare case of a platinum(II) halo-bridged derivative structurally characterized in both bent and planar forms. http://www.mdpi.com/1420-3049/16/7/6082/ Wed, 20 Jul 2011 00:00:00 CEST Molecules 2011-07-20 16 7 Article 6082 6091 1420-3049 Bent Dinuclear Platinum(II) Halo-Bridged Carbonyl Complexes 2011-07-20 doi: 10.3390/molecules16076082 Daniela Belli Dell'Amico Luca Labella Fabio Marchetti http://www.mdpi.com/1420-3049/16/7/5807/ An imidazolium tetrasubstituted cationic porphyrin derivative (the free base and its Zn(II) complex) with five-membered heterocyclic groups in the meso-positions were synthesized using microwave irradiation, and the compounds obtained characterized by 1H-NMR and mass spectrometry. We observed that under microwave irradiation the yield is similar to when the synthesis is performed under conventional heating, however, the time required to prepare the porphyrins decreases enormously. In order to investigate the electronic state of these compounds, we employed UV-Vis and fluorescence spectroscopy combined with quantum chemical calculations. The results reveal the presence, in both compounds, of a large number of electronic states involving the association between the Soret and a blue-shifted band. The Soret band in both compounds also shows a considerable solvent dependence. As for emission, these compounds present low quantum yield at room temperature and no solvent influence on the fluorescence spectra was observed. http://www.mdpi.com/1420-3049/16/7/5807/ Fri, 08 Jul 2011 00:00:00 CEST Molecules 2011-07-08 16 7 Article 5807 5821 1420-3049 Synthesis and Spectroscopic Characterization of Two Tetrasubstituted Cationic Porphyrin Derivatives 2011-07-08 doi: 10.3390/molecules16075807 Antonio E.H. Machado Weverson R. Gomes Diesley M.S. Araújo Hércules S. Miglio Leonardo T. Ueno Rodrigo De Paula José A.S. Cavaleiro Newton M. Barbosa Neto http://www.mdpi.com/1420-3049/16/6/4652/ Novel organometallic complexes of fullerene C80 and aryl ligands were simulated. The nature and characteristics of this family of complexes involving π coordination between the fullerene and a metal centre have been studied from a theoretical point of view. We are particularly interested in complexes where η6 coordination is present, this being the strangest manifestation of known coordinations, and thus we have studied several known and simulated compounds of this kind in order to understand the lack of examples. The presence of other η6 or η5 ligands on the opposite side seems to be an important element aiding the stabilization of these complexes, also inducing the conductive and semiconductive behaviour of the studied species. http://www.mdpi.com/1420-3049/16/6/4652/ Fri, 03 Jun 2011 00:00:00 CEST Molecules 2011-06-03 16 6 Article 4652 4659 1420-3049 On the π Coordination of Organometallic Fullerene Complexes 2011-06-03 doi: 10.3390/molecules16064652 Bertha Molina Liliana Pérez-Manriquez Roberto Salcedo http://www.mdpi.com/1420-3049/16/5/4191/ Organobismuth chemistry was emphasized in this review article due to the low price, low toxicity and low radioactivity characteristics of bismuth. As an environmentally-friendly class of organometallic compounds, different types of organobismuth compounds have been used in organic synthesis, catalysis, materials, etc. The synthesis and property characterization of many organobismuth compounds had been summarized. This review article also presented a survey of various applications of organobismuth compounds in organic transformations, as reagents or catalysts. The reactivity, reaction pathways and mechanisms of reactions with organobismuths were discussed. Less common and limiting aspects of organobismuth compounds were also briefly mentioned. http://www.mdpi.com/1420-3049/16/5/4191/ Fri, 20 May 2011 00:00:00 CEST Molecules 2011-05-20 16 5 Review 4191 4230 1420-3049 Synthesis, Properties Characterization and Applications of Various Organobismuth Compounds 2011-05-20 doi: 10.3390/molecules16054191 Jingfei Luan Lingyan Zhang Zhitian Hu http://www.mdpi.com/1420-3049/16/5/3855/ RuCl3·3H2O was found to be an effective catalyst for reactions of indoles, 2-methylthiophene, and 2-methylfuran with aldehydes to afford the corresponding bis(indolyl)methanes, bis(thienyl)methanes, and bis(fur-2-yl)methanes in moderate to excellent yields. Experimental results indicated that mono(indolyl)methanol is not the reaction intermediate under these reaction conditions. http://www.mdpi.com/1420-3049/16/5/3855/ Mon, 09 May 2011 00:00:00 CEST Molecules 2011-05-09 16 5 Article 3855 3868 1420-3049 RuCl3·3H2O Catalyzed Reactions: Facile Synthesis of Bis(indolyl)methanes under Mild Conditions 2011-05-09 doi: 10.3390/molecules16053855 Hong-En Qu Chen Xiao Ning Wang Kai-Hui Yu Qiao-Sheng Hu Liang-Xian Liu http://www.mdpi.com/1420-3049/16/2/1103/ Logarithms of stability constants, log K1 and log β2, of the first transition series metal mono- and bis-complexes with any of four aliphatic amino acids (glycine, alanine, valine and leucine) decrease monotonously with third order valence connectivity index, 3χv, from Cu2+ to Mn2+. While stability of the complexes with the same metal is linearly dependent on 3χv, stability constants of Mn2+, Fe2+, Co2+, and Ni2+complexes with the same ligand show a quadratic dependence on 3χv. As Cu2+ complexes deviate significantly from quadratic functions, models for the simultaneous estimation of the stability constants, yielding r = 0.999 (S.E. = 0.05) and r = 0.998 (S.E. = 0.11), for log K1 and log β2, respectively, were developed only for Mn2+, Fe2+, Co2+, and Ni2+ complexes with amino acids. http://www.mdpi.com/1420-3049/16/2/1103/ Wed, 26 Jan 2011 00:00:00 CET Molecules 2011-01-26 16 2 Article 1103 1112 1420-3049 Irving-Williams Order in the Framework of Connectivity Index 3χv Enables Simultaneous Prediction of Stability Constants of Bivalent Transition Metal Complexes 2011-01-26 doi: 10.3390/molecules16021103 Ante Miličević Gina Branica Nenad Raos http://www.mdpi.com/1420-3049/15/4/2631/ New phosphoramidite complexes of iron were synthesized and structurally characterized. Reaction of the known chiral phosphoramidites (RO)2PNR’2 (R = binaphthyl, R’ = CH3, 1a; R = binaphthyl, R’ = benzyl, 1b) with [FeBr(Cp)(CO)2] afforded the title compounds [FeBr(Cp)(CO)(1a,b)] (4a,b) in 34 and 65 % isolated yields as mixtures of diastereomers, since both the metal and the ligand are stereogenic. Similarly, reaction of 1b with [Fe(Cp)I(CO)2] in the presence of catalytic [Fe(Cp)(CO)2]2 afforded [Fe(Cp)I(CO)(1b)] (5b) in 81% yield as a mixture of diastereomers. The molecular structures of 4a, 4b and 5 were determined, revealing a pseudo octahedral coordination geometry about the iron center. The new metal complexes are catalytically active in the oxidation of benzylic methylene groups to the corresponding ketones, utilizing t-BuOOH as oxidant (2 mol% catalyst, 36 h, room temperature, 31−80% yield). http://www.mdpi.com/1420-3049/15/4/2631/ Mon, 12 Apr 2010 00:00:00 CEST Molecules 2010-04-12 15 4 Article 2631 2650 1420-3049 New Chiral Phosphoramidite Complexes of Iron as Catalytic Precursors in the Oxidation of Activated Methylene Groups 2010-04-12 doi: 10.3390/molecules15042631 Shejwalkar Rath Bauer