Transition metal complexes with tetrathiometallate anions

In this Τhesis we report the synthesis and study with spectroscopic techniques(UV-Vis and 31Ρ NMR) and Cyclic Voltammetry of the heterometallic complexes of Rh(I)with tetrathiomolybdate and tetrathiotungstate and auxiliary ligands commerciallyavailable phosphites, 1,5 cyclooctadiene (COD), phosphines and diphosphines. Theanionic complexes [L2Rh(μ-S)2MS2] − were characterized with ESI-MS measurements.The complex [{(P(OEt)3)2Rh}2(μ-WS4)] and [{(P(OiPr)3)2Rh}2(μ-WS4)], werecharacterized by X-ray diffraction analysis. Both complexes crystallize in the samespace group C2/c (Z=4) with unit cell dimensions a=17,642(3) Å, b=19.358(3) Å,c=16,002(2) Å and a=20,587(3) Å, b=19.425(3) Å, c=17,698(3) Å, respectively. Thestructures for both complexes show two square planar rhodium fragments with twophosphites binding through the sulfur atoms of a tetrahedral WS4 unit.The detailed DFT study of the electronic structures of [(P(OPh)3)2Rh(μ-S)2MoS2]−and [(COD)Rh(μ-S)2WS2] − has revealed the existence of extended electrondelocalization over the four-membered Rh(μ-S)2M (M=Mo,W) ring and hence thepossibility of electronic communication between the metal centres. The electronicspectrum of [(COD)Rh(μ-S)2WS2] − was studied with TDDFT calculations, and the mainabsorption band in the visible region was assigned to ν(Rh→W) electron transfertransition, which is actually a HOMO−LUMO transition. For the bimetallic and trimetallic complexes of the types [L2Rh(μ-S)2MS2] − and [{L2Rh}2(μ-ΜS4)] (M=Mo,W and L=P(OPh)3, P(O-o-CH3C6H4)3, P(OMe)3, P(OEt)3, P(OiPr)3), it was found that the measured values of the electronic transitions ν(Rh→M) (M=Mo ή W) correlate linearly with the electronic parameter of Tolman, rendering these transitions well-defined ligand electronic parameters, which describe the net donating ability of monodentate and bidentate ligands (CO, COD, phosphites, diphosphines). The study of the variation of the ∆δ(31P) and 1J(Rh−P) of the phosphite complexes with respect to the QALE model electronic parameters χd, πp, and Ear has succeeded in the assessment of the σ and π effects on these NMR spectral parameters.Στην παρούσα διατριβή παρουσιάζεται η σύνθεση και η μελέτη, μεφασματοσκοπικές μεθόδους (UV-Vis και 31P NMR) και κυκλική βολταμμετρία συμπλόκων του Rh(I) με τετραθειομολυβδαινικά και τετραθειοβολφραμικά διανιόντα με βοηθητικούς υποκαταστάτες εμπορικά διαθέσιμους φωσφίτες, 1,5-κυκλοοκταδιένιο ή/και φωσφίνες και διφωσφίνες. Η σύσταση των μονοανιοντικών συμπλόκων του τύπου[L2Rh(μ-S)2MS2] - (M=Mo, W) προσδιορίσθηκε με μετρήσεις ESI-MS. Επιλύθηκαν οι κρυσταλλικές δομές των συμπλόκων [{(P(OEt)3)2Rh}2(μ-WS4)] και[{(P(OiPr)3)2Rh}2(μ-WS4)], τα οποία κρυσταλλώνονται στην ίδια ομάδα χώρου C2/c(Z=4) με διαστάσεις στοιχειώδους κυψελίδας a=17,642(3) Å, b=19.358(3) Å,c=16,002(2) Å και a=20,587(3) Å, b=19.425(3) Å, c=17,698(3) Å, αντιστοίχως. Οι δομές των δύο συμπλόκων δείχνουν δύο επίπεδα τετραγωνικά θραύσματα ροδίου με δύο φωσφίτες, τα οποία γεφυρώνονται από τα άτομα θείου ενός μ-τετραθειοβολφραμικούδιανιόντος.Έγινε λεπτομερής υπολογιστική (DFT) μελέτη της δομής των συμπλόκων[(P(OPh)3)2Rh(μ-S)2MoS2]- και [(COD)Rh(μ-S)2WS2]- η οποία απεκάλυψε την ύπαρξη εκτεταμένου ηλεκτρονικού απεντοπισμού καθ΄ όλη την έκταση των τετραμελών δακτυλίων Rh(μ-S)2M (M=Mo,W) και συνεπώς τη δυνατότητα ηλεκτρονικής επικοινωνίας μεταξύ των μεταλλικών κέντρων. Το ηλεκτρονικό φάσμα του [(COD)Rh(μS)2WS2]− μελετήθηκε με υπολογισμούς TDDFT και η κύρια ταινία απορρόφησης στην ορατή περιοχή αποδόθηκε στην μετάπτωση μεταφοράς ηλεκτρονίου ν(Rh→W), η οποία είναι μία μετάπτωση HOMO-LUMO.Για τα διμεταλλικά και τριμεταλλικά σύμπλοκα των τύπων [L2Rh(μ-S)2MS2]− και [{L2Rh}2(μ-ΜS4)] (Μ=Μο,W και L=P(OPh)3, P(O-o-CH3C6H4)3, P(OMe)3, P(OEt)3,P(Oi Pr)3), βρέθηκε ότι οι πειραματικές τιμές των ηλεκτρονικών μεταπτώσεων ν(Rh→M)(M=Mo ή W) συσχετίζονται γραμμικά με την ηλεκτρονική παράμετρο του Tolman (ΤΕΡ)και ότι αποτελούν καλώς καθορισμένες ηλεκτρονικές παραμέτρους υποκαταστατών, οι οποίες περιγράφουν την καθαρή δοτική ικανότητα των φωσφιτών. Mέσω της μελέτης της μεταβολής της ∆δ(31P) και της 1J(Rh-P) των ανωτέρω συμπλόκων, συναρτήσει των ηλεκτρονικών παραμέτρων της μεθόδου QALE, χd, πp καιEar επετεύχθη η απόδοση των σ και π επιδράσεων των υποκαταστατών στις ανωτέρω 31Ρ NMR παραμέτρους

Tetrathiomolybdate Complexes of Rhodium(I) with Molybdenum-Rhodium Interactions

The synthesis and characterization of the tetrathiomolybdatorhodium(I) monoanionic complexes [L2Rh(-S)2MoS2]- (L = CO (3), P(OPh)3 (4), P(O-o-Tol)3 (P(o-CH3C6H4)3; 5), P(OMe)3 (6), P(OEt)3 (7), P(O-i-Pr)3 (8); L2 = COD (1,5-cyclooctadiene; 2), cis-dppen (cis-Ph2PCH - CHPPh2; 9), dppe (Ph2PCH2CH2PPh2; 10), dppb (Ph2P(CH2)4PPh2; 11)) is presented. The complex 2 (NEt4+ salt) was characterized by X-ray diffraction analysis. A detailed DFT study of the electronic structures of 2-4 and 6-8 has revealed the existence of extended electron delocalization over the four-membered Rh(-S)2Mo ring and hence the possibility of electronic communication between the metal centers. The electronic spectra were studied with TDDFT calculations, and the main absorption band in the visible region was assigned to ν(Rh→Mo) electron transfer transition, which is actually a HOMO-LUMO transition. The ν(Rh→Mo) transition was found to correlate linearly both with Tolmans electronic parameter of the phosphite ligands and the calculated HOMO-LUMO gap of the complexes, rendering it a well-defined ligand electronic parameter, which describes the net donating ability of monodentate and bidentate ligands (CO, COD, phosphites, diphosphines). The study of the variation of Δδ(31P) and 1J(Rh-P) of the phosphite complexes with respect to the QALE model electronic parameters χd, πp, and Ear has succeeded in the assessment of the σ and π effects on these NMR spectral parameters. © 2016 American Chemical Society

Heterotrimetallic tetrathiomolybdate and tetrathiotungstate complexes of rhodium(I) and copper(I) with Rh-Mo(W)-Cu interactions

The synthesis and characterization of the monoanionic heterotrimetallic (d8···d0···d10) complexes [L2Rh(μ-S)2M(μ-S)2CuCl]− (L = P(OPh)3, P(O-o-Tol)3 (P(O-o-CH3C6H4)3), P(OMe)3, P(OEt)3, P(OiPr)3; L2 = COD (1,5-cyclooctadiene), cis-dppen (cis-Ph2PCH = CHPPh2); M = Mo, W) is presented. The complex (NEt4)[(cis-dppen)Rh(μ-S)2W(μ-S)2CuCl] was characterized by X-ray diffraction analysis. The detailed DFT study of the electronic structure of the complexes with P(OMe)3 and COD ligands has revealed the existence of extended electron delocalization over the atom-sharing (spiro) four-membered rings system Rh(μ-S)2M(μ-S)2Cu and the possibility of electronic communication between the terminal metal centers. The electronic spectra of the complexes with P(OMe)3 ligands were studied with TDDFT calculations and the main absorption band in the visible region was assigned to ν(Rh → Mo/W) electron transfer transition. The ν(Rh → Mo/W) transition was found to correlate linearly with Tolman's electronic parameter of the phosphite ligands, making it an electronic parameter for the ligands studied. Finally, the study of the dependence of Δδ(31P) and 1J(Rh-P) of the phosphite complexes, with respect to the QALE model electronic parameters χd, πp and Ear, has succeeded in the assessment of the σ and π effects on these NMR spectral parameters. © 202

Tetrathiomolybdate Complexes of Rhodium(I) with Molybdenum–Rhodium Interactions

Producción CientíficaThe synthesis and characterization of the tetrathiomolybdatorhodium(I) monoanionic complexes [L2Rh(μ-S)2MoS2]− (L = CO (3), P(OPh)3 (4), P(O-o-Tol)3 (P(o-CH3C6H4)3; 5), P(OMe)3 (6), P(OEt)3 (7), P(O-i-Pr)3 (8); L2 = COD (1,5-cyclooctadiene; 2), cis-dppen (cis-Ph2PCH═CHPPh2; 9), dppe (Ph2PCH2CH2PPh2; 10), dppb (Ph2P(CH2)4PPh2; 11)) is presented. The complex 2 (NEt4+ salt) was characterized by X-ray diffraction analysis. A detailed DFT study of the electronic structures of 2–4 and 6–8 has revealed the existence of extended electron delocalization over the four-membered Rh(μ-S)2Mo ring and hence the possibility of electronic communication between the metal centers. The electronic spectra were studied with TDDFT calculations, and the main absorption band in the visible region was assigned to ν(Rh→Mo) electron transfer transition, which is actually a HOMO–LUMO transition. The ν(Rh→Mo) transition was found to correlate linearly both with Tolman’s electronic parameter of the phosphite ligands and the calculated HOMO–LUMO gap of the complexes, rendering it a well-defined ligand electronic parameter, which describes the net donating ability of monodentate and bidentate ligands (CO, COD, phosphites, diphosphines). The study of the variation of Δδ(31P) and 1J(Rh–P) of the phosphite complexes with respect to the QALE model electronic parameters χd, πp, and Ear has succeeded in the assessment of the σ and π effects on these NMR spectral parameters