Millennium Nucleus
Molecular Engineering for Catalysis and Biosensors

What we learned...


Role of the main adsorption modes in the interaction of the dye [COOH–TPP-Zn(II)] on a periodic TiO2 slab exposing a rutile (110) surface in a dye-sentized solar cell
Tatiana Gomez, Ximena Zarate, Eduardo Schott, and Ramiro Arratia-Perez
RSC Adv., 2014,4, 9639-9646 [0.000, 0]
DOI:   10.1039/C3RA47067A
The high solar-to-electric-power conversion efficiency reported for 5-(4-carboxylphenyl)-10,15,20-tetrakis (2,4,6-trimethylphenyl) porphyrinatozinc(II) (TPP-Zn(II)) prompted us to study at a molecular level the interaction of this dye on the rutile surface. The –COOH group was included in the complex to anchor the dye onto the semiconductor oxide. Three main modes of molecular adsorption of the anchoring group on the oxide surface were studied, and vibrational analysis was carried out to characterize it as either a minimum energy or a transition state structure. To investigate the geometrical and electronic structures of the different modes of COOH–TPP-Zn(II) adsorption on the periodic TiO2 slab with exposed rutile (110) surfaces, we employed time-dependent density functional theory to study the optical properties of the isolated molecule TPP-Zn(II) (which was used in the DSSC), followed by periodic DFT calculations in the completed system (COOH–TPP-Zn(II) on the periodic TiO2 slab). This procedure leads to a clear identification of the most stable position of the anchoring group, that binds strongly the dye on the surface and simultaneously facilitates the electron injection. On the other hand, frontier molecular orbital spatial distributions, and the energy diagram of the electronic density of states of the dye-surface system, suggest that the dye is capable of electron injection into TiO2, as has been shown from experiments. Our computational approach is able to provide considerable insight into the electronic structure of the bond system of TPP-Zn(II)–TiO2 and to get insight into the anchoring modes, which are very important for the coupling between the dye and the semiconductor surface. This leads to an effective photocurrent energy conversion in a DSSC device.

Simultaneous electrochemical detection of dopamine, ascorbic acid and uric acid using copper-phthalocyanine functionalized MWCNTS
Mamie Sancy, J. Francisco Silva, Jorge Pavez and José H. Zagal
J. Chil. Chem. Soc. 2013, 58(4), 2117-2121 [0.000, 0]
Multiwalled carbón nanolububes functionalized with amino groups (MWCNT-NH2)and further modified with copper-phthalocyaninetetrasulphonate (4β(S03) CuPc) were used for preparing a hybrid electrode [MWCNT-NH2/4β(S03)CuPc/GC] using glassy carbón (GC) as a support. This hybrid electrode was tested for the delection of dopamine (DA) in the presencc of ascorbic acid (AA) and uric acid (UA) in a PBS buffer solution at pH 6.8. The presence of the macrocyclic increased the rcsolution of the oxidation signals of AA, DA and UA into three very well distinct oxidation peaks. This effect was enhanced when the complex is adsorbed on multiwalled carbón nanotubes. In addition, the hybrid films provide a simple method for selective detection of DA, AA and UA in biological samples. The calibration curves for DA were obtaincd over the range of 1x10-6 - 1x10-3 M, obtaining a good selectivity and sensitivity.

Fundamental Studies on the Electrocatalytic Properties of Metal Macrocyclics and Other Complexes for the Electroreduction of O2
Justus Masa, Kenneth I. Ozoemena, Wolfgang Schuhmann, and José H. Zagal
Chapter 7, p. 157-212, in .... [0.000, 0]
The high prospects of exploiting the oxygen reduction reaction (ORR) for lucrative technologies, for example, in the fuel cells industry, chlor-alkali electrolysis, and metal-air batteries, to ñame but a few, have prompted enorrnous research interest in the search for cost-effective and abundant catalysts for the electrocatalytic reduction of oxygen. This chapter describes and discusses the electrocatalysis of oxygen reduction by metallomacrocyclic complexes and the prospect of their potential to be used in fuel cells. Since the rnain interest of most researchers in this field is to design catalysts which can achieve facile reduction of O2 at a high thermodynamic efficiency, this chapter aims to bring to light the research frontiers uncovering important milestones towards the synthesis and design of promising metallomacrocyclic catalysts which can accomplish the four-electron reduction of O2 at low overpotential and to draw attention to the fundamental requirements for synthesis of improved catalysts. Particular attention has been paid to discussion of the common properties which cut across these complexes and how they may be aptly manipulated for tailored catalyst synthesis. Therefore, besides discussion of the progress attained with regard to synthesis and design of catalysts with high selectivity towards the fourelectron reduction of O2, a major part of this chapter highlights quantitative structure—activity relationships (QSAR) which govern the activity and stability of these complexes, which when well understood, refined, and carefully implemented.

Unusual behaviour of perfluorinated cobalt phthalocyanine compared to unsubstituted cobalt phthalocyanine for the electrocatalytic oxidation of hydrazine. Effect of the surface concentration of the catalyst on a graphite surface
José H. Zagal, Daniela A. Geraldo, Mamie Sancy, and Maritza A. Paez
J. Serb. Chem. Soc. 78 (12) 2039–2052 (2013) [0.000, 0]
DOI:   10.2298/JSC131024123Z
We have found that CoPc and 16(F)CoPc when adsorbed on graphite electrode exhibit voltammograms in alkaline solution (0.2M NaOH) that show the typical redox peaks attributed to the Co(II)/(I) reversible. The peak potential for CoPc is independent of surface concentration of the catalyst. In contrast, for 16(F)CoPc the Co(II)/(I) redox process shifts to more negative potentials when the surface concentration of the catalyst increases. In a volcano correlation of log (i/G)E (activity per active site) versus Co (II)/(I) formal potential of catalyst (using several CoN4 chelates) CoPc appears in the ascending portion (activity increases with the Co (II)/(I) redox potential) whereas 16(F)CoPc appears in the region where activity decreases with the redox potential. In a plot of log (i/G)E versus the Co(II)/(I) formal potential of 16(F)CoPc the declining portion of the volcano is reproduced for one single complex. So 16(F)CoPc at different surface concentrations behaves as Co complexes having different redox potential in the declining portion of the volcano plot, when the activity is normalized for the surface concentration. This is not observed for CoPc.

Electrocatalytic activity of modified gold electrodes based onself-assembled monolayers of 4-mercaptopyridine and 4-aminothiophenol on Au(111) surfaces chemically functionalized with substituted and unsubstituted iron phthalocyanines
J. Francisco Silva, Jorge Pavez, Carlos P. Silva, José H. Zagal
Electrochimica Acta 114 (2013) 7–13 [0.000, 0]
DOI:   10.1016/j.electacta.2013.10.017
Systems containing self-assembled monolayers (SAMs) of thiols on metallic and nonmetallic surfaces are attractive as they provide structurally well-defined surfaces with a controllable chemical functionality, in addition to their stability and stiffness. These special features have inspired several studies addressed to electron transport ability through the SAMs and to the influence of the chemical functionality of thiols. We studied the electrocatalytic activity for the oxidation of l-cysteine of gold electrodes modified with self-assembled monolayers of 4-mercaptopyridine (4MPy) and 4-aminothiophenol (4ATP) on Au(111) surfaces chemically functionalized with substituted and unsubstituted Fe(II)-phthalocyanines (FePc). Attention was focused on the study of the effect of the thiol-end-FePc on the electron transfer rate from l-cysteine to the gold–SAM–FePc assembly, as well as on the effect of Pc-ring substituents on the ET kinetics. It is found that the effect of substituents on the Pc-ring (using Hammett parameters) on the Fe(III)/(II) redox potential is weak when FePc molecules are confined directly on Au and with the 4MPy SAMs/FePc, but their more pronounced when FePc molecules are located on the outermost position of the SAM assembly with a 4ATP molecules.

Theoretical insights into the adsorption of neutral, radical and anionic thiophenols on gold(111)
S. Miranda-Rojas, Alvaro Muñoz-Castro, Ramiro Arratia-Perez and Fernando Mendizábal
Phys.Chem. Chem. Phys., 2013, 15, 20363 [0.000, 0]
DOI:   10.1039/c3cp53591f
The interaction of thiol and thiolate containing molecules with gold (S–Au) has gained increasing interest because of its applications in molecular electronic devices and catalysis. In this context, the enhanced conductivity of thiophenol compared to alkanethiol represents an opportunity to develop more sensitive and selective gold-based devices by incorporating molecules with the aryl–thiol moiety into their structures. As has been proposed earlier, the thiol moiety is deprotonated after binding to gold, hence, we present here a comparative study of the S–Au bond strength between several neutral and deprotonated aromatic–sulfur systems in their anionic and radical forms with a detailed description of the nature of this interaction. The study was performed by means of computational chemistry methods, using a cluster of 42 Au atoms as a model of the Au(111) surface that allowed us to provide new chemical insights to control the S–Au interface interaction strength. Our results revealed that the thiophenols–gold interaction is mainly dispersive where the interaction energies range between 31 and 43 kcal mol-1. The radical and anionic thiophenolates–gold interaction increases due to a strong charge transfer character, depicting interaction energies in the range of 50 to 55 kcal mol-1 and 62 to 92 kcal mol-1, respectively. These results suggest that for the anionic thiophenolate the binding strength can be tailored according to the electron–donor capabilities of the ligand which in turn can be finely tuned by several substituents. Our results are of possible impact for the design of new devices.

Golden Endohedral Main-Group Clusters, [E@Au12]q-: Theoretical Insights Into the 20-e Principle
Alvaro Muñoz-Castro
J. Phys. Chem. Lett., 2013, 4 (19), 3363–3366 [0.000, 0]
DOI:   10.1021/jz401622m
The inclusion of a transition metal (M) into an icosahedral Au12 cage ([M@Au12]q), was theoretically predicted prior to its experimental characterization on the basis of the jellium model, where the titled system is in accordance with the 18-ve principle fulfilling a 1s21p61d10 electronic configuration. In contrast, the inclusion of a p-block element (E) seems not to follow such principle, leading to an open-shell state that in turn exhibits a Jahn–Teller distortion. Hence, the icosahedral structure is no longer the more stable situation. We rationalize the electronic structure of [E@Au12],q denoting the interaction between the endohedral element and the golden cage, which rise to a 1s21p62s21d10 electronic configuration requiring 20-ve as an extension to the 18-ve principle. The 20-ve count is valid in almost the whole series, with the exception given by E = N, O, F, Cl, and Br.

Optimizing the reactivity of surface confined cobalt N4-macrocyclics for the electrocatalytic oxidation of L-cysteine by tuning the Co(II)/(I) formal potential of the catalyst
Miguel A. Gulppi, Francisco J. Recio, Federico Tasca, Gonzalo Ochoa, Juan F. Silva, Jorge Pavez, José H. Zagal
Electrochimica Acta, In Press [0.000, 0]
DOI:   10.1016/j.electacta.2013.07.230
The redox potential of macrocyclic complexes is a very predictive reactivity index for the electrocatalytic activity of these molecules and it can be easily measured under the same conditions of the kinetic experiments. It reflects directly the catalytic activity of a given complex. We have investigated the effect of the Co(II)/(I) formal potential of CoN4 macrocyclics complexes on the catalytic activity of a series of Co porphyrins and Co phthalocyanines for the electrooxidation of l-cysteine. The complexes were adsorbed on ordinary pyrolytic graphite. A correlation of log i (at constant potential) versus the Co(II)/(I) formal potential of the catalysts gives a volcano curve. Our results clearly show that the Co(II)/(I) formal potential of N4-macrocyclic complexes needs to be adjusted to values around ?0.96 V vs. SCE to obtain the highest catalytic activity for the oxidation of l-cysteine at pH 13.

Antenna Effect by Organometallic Chromophores in Bimetallic d–f Complexes
Franklin Ferraro, Dayan Pa?ez-Herna?ndez, Juliana A. Murillo-Lo?pez, Alvaro Mun?oz-Castro, and Ramiro Arratia-Pe?rez
J. Phys. Chem. A, 2013, 117 (33), pp 7847–7854 [0.000, 0]
DOI:   10.1021/jp406208e
The nature of the intermetallic bond in a series of complexes of the type [Cp2–TM–M–Cp2] (where TM = Re and M = Y, La, Lu, Yb, Ac; also TM = Os and M = Th; Cp = cyclopentadienyl ligand) have been studied by relativistic two-component density functional theory (DFT) calculations. The results obtained in this work show that the interaction between the transition metal and lanthanide atoms is mainly ionic in all cases, while for the case of actinide atoms this interaction becomes significantly more covalent. The effective direction of the electron transfer between the Re?Ac or Os?Th centers allows us to propose that the [Cp2ReAcCp2] and [Cp2OsThCp2] complexes are ideal candidates for near-infrared (NIR) technologies since their absorption spectra show some transitions over 600 nm. We also observed a shifting of the absorption spectrum of around 100 nm of the [Cp2Re] fragment when is compared against the absorption spectrum of the entire complex. This behavior allows us to argue that the [Cp2Re] fragment is a good antenna chromophore due to the possibility of charge transfer transitions from this fragment to the f shell in lanthanide or actinide elements studied here.

Theoretical study of the binding strength and magnetical response properties involved in the formation of the π-donor/π-acceptor [TTF–CBPQT]4+ host–guest system
Carolina Olea Ulloa, Miguel Ponce Vargas, Raul Guajardo Maturana, Alvaro Muñoz-Castro
Polyhedron, 2013, 54, 119-122 [0.000, 0]
DOI:   10.1016/j.poly.2013.02.022
The forces involved into the formation of the ?-donor/?-acceptor host–guest system [TTF–CBPQT]4+ has been evaluated theoretically by using dispersion corrected DFT (DFT-D) methodologies. Three models were taken into account as follows, solely the [TTF–CBPQT]4+ system (model 1), [TTF–CBPQT][(PF6)4] (2) and [TTF–CBPQT][(PF6)4] plus acetonitrile as solvent via the continuum approach for the solvation treatment (COSMO) (3), which denotes the variation of the interaction energy according to the employed model. For model 3, the total formation (binding strength) energy calculated amounts to −8.98 kcal/mol, which is in the range of the available experimental data. In addition the through-the-space magnetic response is described, in order to gain more insights into the π-donor/π-acceptor host–guest interaction.

Tuning the Fe(II)/(I) formal potential of the FeN4 catalysts adsorbed on graphite electrodes to the reversible potential of the reaction for maximum activity: Hydrazine oxidation
Francisco Javier Recio, Paulina Cañete, Federico Tasca, Cristian Linares-Flores, José Heráclito Zagal
Electrochemistry Communications 30 (2013) 34–37 [0.000, 0]
DOI:   10.1016/j.elecom.2013.01.024
In classical volcano correlations in electrocatalysis, the shape of (log io) plots versus the binding energy of the reactant to active sites, the maximum activity is associated to a situation where the surface coverage of reactant species is equal to 0.5 corresponding to a free energy of adsorption of the reactant equal to zero. When studying electrochemical reactions catalysed by macrocyclic transition metal complexes adsorbed on graphite electrodes, volcano correlations are found when plotting the activity versus the formal potential of the catalyst for several reactions, assuming that the formal potential is somehow related to the free energy of the adsorption of the reacting molecule. In this work we offer an interpretation different from that given in the literature for these correlations for the electrooxidation of hydrazine. The highest catalytic activity is achieved when the formal potential of the catalyst approaches the N2H4/N2 reversible potential. In contrast, if log i (normalized for the actual surface concentrations of Fe(II) active sites at constant potential) is plotted versus the difference between the Fe(II)/(I) formal potential of the catalysts and the standard potential of the N2H4/N2 reaction, the correlation is linear with a slope close to 2RT/F.

Matching the Catalyst Co(II)/(I) Formal Potential of a Macrocyclic Complex to the Reversible Potential of Hydrazine Oxidation for the Highest Activity
Francisco Javier Recio, Daniela Andrea Geraldo, Paulina Cañete and José Heráclito Zagal
ECS Electrochemistry Letters, 2013, 2 (4) H16-H18 [0.000, 0]
DOI:   10.1149/2.003304eel
In this work we have re-interpreted volcano correlations for the oxidation of hydrazine catalyzed by CoMN4 catalysts and found that the highest catalytic activity is observed when the formal potential of the catalyst matches the reversible potential of the reaction, i.e. the hydrazine/dinitrogen reversible potential, that is ?0.4959 V vs. SCE at pH 13. This clearly shows that the formal potential of the catalysts needs to be “tuned” or to be very close to the reversible potential of the target molecule to undergo an ET process. This is also true for other reactions we are studying.

Molecular properties of two related families of substituted [Ru(2,2′:6′,2″-Terpyridine)2]2+ for application as sensitizers in dye-sensitized solar cells
Eduardo Schott, Ximena Zarate, Ramiro Arratia-Perez
Dyes and Pigments, 2013, 97 (3), 455-461 [0.000, 0]
DOI:   10.1016/j.dyepig.2013.01.006
A theoretical study of two families of related compounds of 4′-R substituted 2,2′:6′,2″-terpyridines (TP) with Ruthenium as central metal is presented (one family is homoleptic and the other family is heteroleptic). The influence of the 4′-R substituent over the electronic structure, reactivity indexes and the electronic transitions in the UV–Vis spectra is studied. A proposal of a group of dyes not synthesized yet that could be efficient dyes to sensitize a semiconductor like TiO2 in an energy conversion device like a DSSC is made. Due to the presence of the carboxylic anchor group, the results of the direction of the calculated excitations and the charge transfer of the TP ligand, suggest that the most effective dyes are the heteroleptic TP with an electron-donor substituent over one terpyridine ligand and one carboxylic acid group in the 4′ position of the second TP ligand.

Theoretical study of complexes of the type [PT3(M-L)3(L`)3]-X (L=CO,SO2,CNH; L`=PH3,CNH; X=TL+, HG0, MPH3 + (M = CU, AU, AG))
Fernando Mendizabal, Daniela Donoso, Richard Salazar
J. Chil. Chem. Soc., 2013, 58 (1), [0.000, 0]
The interaction between the [Pt3(µ-L)3(L`)3] cluster (L = CO, SO3, CNH; L` = PH3, CNH) and a series of fragments X (Tl+, Hg(0), AuPH3+, CuPH3+ and AgPH3+) was studied using ab initio methodology. The calculations suggest that the complexes formed are stable. We have studied these complexes at the HF, MP2, B3LYP and PBE levels of theory. The magnitude of the interaction energies and Pt3-MPH3 distances indicate a substantial covalent character of the bond. On the other hand, in [Pt3(µ-L)3(L`)3]-X (Tl+ and Hg) the energy magnitudes are in the order of metallophilic interaction, which indicates that the dispersion and ionic terms are found as the main contribution to stability. These results have been confirmed by orbital diagrams. In addition, the Fukui index of electrophilic attack and electrophilicity index on the [Pt3(µ-L)3(L`)3] clusters were used to explore possible sites that may play a role in chemical reactivity.

Theoretical Study of Sensitizer Candidates for Dye-Sensitized Solar Cells: Peripheral Substituted Dizinc Pyrazinoporphyrazine-Phthalocyanine Complexes
Ximena Zarate, Eduardo Schott, Tatiana Gomez, and Ramiro Arratia-Pérez
J. Phys. Chem. A, 2013, 117 (2), 430-438 [0.000, 0]
DOI:   10.1021/jp3067316
We have carried out a theoretical study of the geometrical and electronic structures of a family of planar dimers constituted by zinc(II) pyrazinoporphyrazine and zinc(II) phthalocyanine with peripheral electron-donating and electron-withdrawing substituents R [where R = —OH (1), —C(CH3)3 (2), —CH3 (3), —C6H5 (4), —H (5), —CO2H (7), —NO2 (7), and —PO3H2 (8)]. The complexes are connected by varying the bridge (B) ligand, where, in 19, B is —CH= and, in 1012, B is —N=, —O—, and —S—, respectively. The —CO2H group was included in complexes identified as 912. This was done because of the known properties of this group in acting as an anchor to adsorb a dye onto a semiconductor oxide. The aim of this work was to provide a useful theoretical basis for the design and screening of new potential dye candidates to be used in these devices, based on the properties of the dyes suitable for their good performance in solar cells, such as frontier molecular orbital spatial distributions; charge-separated states in the electronic transitions in the visible region of the spectrum; and importantly, the energy diagram of the frontier MOs of these dyes and the conduction band (CB) of the semiconductor, where the LUMO energy levels that are above of the CB suggest which dyes are capable of electron injection into TiO2. In this sense, it is expected that complexes 15 and 912 should be very promising dyes to act as sensitizers. Finally, a linear correlation was found between the HOMO and LUMO energies of all of the systems and the Hammett constants, where these molecular orbitals become more stable when R is more electron-withdrawing.

Trimetallic deltahedral Zintl ions [Sn9–mnGemBin](4–n)– for n = 1–4 and m = 0–(9 – n): a theoretical survey with prediction and rationalization of the possible structures
Alvaro Muñoz-Castro and Slavi C. Sevov
Phys. Chem. Chem. Phys. 2013,15, 986-991 [0.000, 0]
DOI:   10.1039/C2CP43196C
The recent discovery of trimetallic deltahedral Zintl ions based on Sn, Ge, and Bi revealed the possibility to obtain such clusters with a variety of different Sn/Ge/Bi ratios. Although only the dimer [(BiSn6Ge2)–(Ge2Sn6Bi)]4– was structurally characterized, a number of other nine-atom clusters with various stoichiometries were detected by electrospray mass spectrometry. The lack of structural data for the latter persuaded us to use relativistic density functional calculations in order to determine and rationalize theoretically the most stable structure conformation of each cluster and the positional preferences for the different atoms in the series [Sn9–mnGemBin](4–n)– where n = 1–4 and m = 0–(9 – n). The analysis revealed strong dependence of the cluster geometry on the cluster stoichiometry and revealed sites with significantly different charge distribution. In addition, we introduce a parameter [curly or open phi] based on certain angles in order to rationalize the obtained structures as monocapped square antiprisms (C4v), tricapped trigonal prisms (D3h), or intermediates (C2v).

On the magnetic behavior of spherical aromatic compounds. Insights from the closo-[B12H12]2− cluster through chemical shift tensor maps
Alvaro Muñoz-Castro
Chem. Phys. Lett. 2013, 555, 282–285 [0.000, 0]
DOI:   10.1016/j.cplett.2012.10.083
We employ density functional methods in order to gain a deeper understanding into the magnetic behavior of the archetypal closo-[B12H12]2− cluster revealing the axis dependence of the spherical aromaticity phenomena through the graphical representation of the induced magnetic field. The analysis of the different components of the through-the-space chemical shift tensor (?ij, i,j = xyz), given by the anisotropic shielding surface (?aniso) introduced here, allows to recognize anisotropic zones arising from the spherical aromatic behavior in conjunction to the expected isotropic region observed as a sphere of radius 0.6 Å confined at the center of the icosahedral cage.

Effects of the peripheral substituents (–NH2, –OH, –CH3, –H, –C6H5, –Cl, –CO2H and –NO2) on molecular properties of a Ni-Porphyrazine dimers family
Ximena Zarate, Eduardo Schott, Ramiro Arratia-Pérez
Polyhedron 2013, 50, 131–138 [0.000, 0]
DOI:   10.1016/j.poly.2012.10.041
A theoretical study of the electronic structure, UV–Vis absorption spectra, reactivity and EPR parameters using density functional theory (DFT) and its extension time dependent-density functional theory (TD-DFT) was performed for a family of paramagnetic Ni(II)-Porphyrazines dimers connected by Ni(III)-dithiolene, with general formula [Ni(II)PzR6Ni(III)S4PzR6Ni(II)]1− where the peripheral substituents R are –NH2 (1), –OH (2), –CH3 (3), –H (4), –C6H5 (5), –Cl (6), –CO2H (7) and –NO2 (8)). The simulated UV–Vis absorption spectra exhibit the usual B or Soret and Q bands. The energies of the electronic transitions, the g-tensors and the simulated EPR spectrum are in good agreement with previously reported experimental data. The results show that the odd electron in complexes with R being electron donor are delocalized over the bridge fragment and the systems with R being electron withdrawing are delocalized over the macrocycles Pz. Thus, along with the frontier MOs analysis and reactivity indexes, it was possible to conclude that the character of the peripheral substituents R affect the reactivity of this kind of systems where the most reactive are those with R being electron donor. In addition, the effect of the R groups on the frontier MOs energies is showed by the correlation of HOMO, LUMO and HOMO–LUMO gap energies with the Hammett constants. On the other hand, charge transfer from the ligands to the Ni atoms and back-donation from the Ni atoms to the ligands is observed in the charge transfer analysis.

A new heterobimetallic manganese–rhodium carbonyl complex derived from partially alkylated s-indacene
César Morales-Verdejo, Luciano Oehninger, Iván Martínez-Díaz, Desmond Mac-Leod Carey, Ramiro Arratia-Pérez, Ivonne Chávez, Juan Manuel Manríquez
Inorg. Chim. Acta 2013, 394, 132-139 [0.000, 0]
DOI:   10.1016/j.ica.2012.08.010
This work describes the synthesis and characterization by means of 1H, 13C NMR and FT-IR spectroscopies of new heterobinuclear carbonylated complex derived from partially alkylated s-indacene. The heterobimetallic complex [(CO)3Mn(2,6-diethyl-4,8-dimethyl-s-indaceneiide)Rh(COD)] 1 was synthesized from the monometallic specie [(CO)3Mn(2,6-diethyl-4,8-dimethyl-1-hydroindacenide)] and [Rh(µ-Cl)(COD)]2. Secondly, its respective carbonylated complex [(CO)3Mn(2,6-diethyl-4,8-dimethyl-s-indaceneiide)Rh(CO)2] 2 was obtained by under an atmosphere of carbon monoxide in hexanes. Theoretical calculations of these two compounds were carried out to gain further understanding of these novel molecular systems.