Complexos de ouro(I,III) desenhados para ataque seletivo e inibição de proteínas zinc finger

Orientador: Pedro Paulo CorbiTese (doutorado) - Universidade Estadual de Campinas, Instituto de QuímicaResumo: Muitas abordagens complementares têm sido utilizadas para inativar a proteína zinc finger NCp7 do vírus HIV-1 para uso terapêutico. Os resíduos de cisteína na proteína do HIV-1 (NCp7) são alguns dos resíduos mais nucleofílicos dentre todos os tiolatos ligados ao zinco nesta proteína. Metais ricos em elétrons, tais como Au(I), são particularmente adequados para o desenho de complexos metálicos ejetores de zinco porque, como ácidos de Lewis moles, eles têm alta afinidade por resíduos de Cys. Sem a estrutura tridimensional adequada, o NCp7 é inativado e se torna incapaz de reconhecer sequências específicas de ácidos nucleicos. Uma série de complexos de Au(I) com a estrutura geral [Au(L)(PR3)] (R = Et ou Cy) foi desenhada. Os dois resíduos aromáticos na estrutura do NCp7 (Phe16 e Trp37) são responsáveis por interações do tipo ? com resíduos de purina e pirimidina com RNA e, para a introdução de um componente de seletividade adicional nas estruturas dos compostos desenhados, um ligante L aromático foi comparado ao Cl lábil. A auranofin, um composto ouro(I)-fosfina "padrão" que contém um tioaçúcar coordenado à porção {Au(Et3P)}, também foi avaliada dentro da séries de compostos contendo Et3P. Tanto a natureza da fosfina como a natureza de L afetam a reatividade com o NCp7, afetando também a esfera de coordenação final do Au incorporado à proteína. O primeiro passo é o ataque eletrofílico dos compostos de Au(I)-fosfina nos resíduos coordenados com Zn, formando uma espécie heterobimetálica {R3PAu}-ZnF. Duas vias alternativas se abrem a partir daqui. Na via mais típica, após a ejeção do Zn, a porção {R3PAu} pode permanecer coordenada em um resíduo Cys e, após a perda da fosfina, levar ao gold finger de coordenação Cys-Au-Cys (AuF). Compostos menos reativos, como [Au(dmap)(Et3P)], permitem estudar os estágios iniciais deste mecanismo, a partir de espécies como {Et3PAu}-apoNCp7 por exemplo. O uso de tempos de incubação mais longos ou a utilização de compostos mais reativos, como os precursores contendo cloreto, fornecem informações sobre as espécies finais. Em um caminho alternativo, observado para o composto modelo auranofina, a fração {R3PAu} se coordena a um resíduo His e o AuF final obtido a partir desta via possui esfera de coordenação Cys-Au-His. Embora o Au(III) não seja muito estável em condições biológicas devido ao seu alto potencial de redução e à rápida troca de ligante, muitos compostos recentes contendo Au(III) foram racionalmente desenhados pela seleção de ligantes que estabilizem o Au(III). Os compostos de Au(III) avaliados até agora como inibidores de ZnF frequentemente sofrem redução a Au(I) com a perda de todos os ligantes, sendo comumente aceito que o estado de oxidação do ouro incorporado à proteína na forma de {AuF} é +1 . Com os ligantes certos, o Au(III) se torna estável mesmo na presença de peptídeos com alto teor de cisteína, tais como ZnFs. Aqui, exploramos o composto organometálico [Au(bnpy)Cl2] (bnpy = 2-benzilpiridina desprotonada) em comparação com uma série de complexos de Au(III) com a coordenação bidentada ?2N,N? do tipo quelato de ligantes N^N doadores (2,2'-bipiridina, 4,4'-dimetil-2,2'-bipiridina e 1,10-fenantrolina). O composto organometálico [Au(bnpy)Cl2] apresentou um mecanismo sui generis de ejeção de zinco, nunca antes relatado para qualquer composto metálico, que consiste na transferência do ligante bnpy para um resíduo de Cys da proteína alvo, levando à formação de uma ligação C-S. Determinar a esfera de coordenação do Au em AuFs obtidos pela interação de complexos de Au(I) e Au(III) com proteínas ZnF é um desafio interessante e, para esse fim, utilizamos duas abordagens inovadoras para obter informações estruturais em solução. A técnica Travelling-Wave Ion Mobility (TWIM) acoplada à espectrometria de massas (MS) foi utilizada para avaliar a interação do composto de Au(I) [AuCl(Et3P)] com duas proteínas ZnF modelo que diferem quanto à esfera de coordenação do Zn: NCp7 ZnF2 ( Cys3His) e também o terceiro dedo do fator de transcrição humano Sp1 (Cys2His2). Além disso, a espectroscopia de absorção de raios X (XAS) foi utilizada em uma abordagem de "dupla sonda" para monitorar o estado de oxidação, mudanças de esfera de coordenação e mudanças de geometria do Au e do Zn em reações de duas séries de compostos. Na primeira série, dois compostos de Au(I) ([AuCl(Et3P)] e auranofina) foram comparados ao interagir com dois alvos ZnF, NCp7 ZnF2 e Sp1 ZnF3. Os dados de TWIM-MS e XAS indicam que o [AuCl(Et3P)] leva à formação de um AuF Cys-Au-His ao interagir com Sp1 ZnF3, ao contrário do AuF Cys-Au-Cys identificado na interação com NCp7 ZnF2. Finalmente, o XAS foi utilizado para comparar a interação de dois compostos do tipo [Au(dien)L]n+ (dien = dietilenotriamina; L = Cl, n = 2; L = dmap, n = 3) com os mesmos dois zinc fingers e demonstraram que o [Au(dien)(dmap)]3+ mantém a esfera de coordenação AuN4 e a geometria quadrada do Au(III), sugerindo que o composto permanece sem reagir ou se comporta como um ejetor de Zn não covalente. Os dados de MS confirmaram a existência da ejeção de Zn e a levaram à identificação de um aduto não-covalente entre [Au (dien)(dmap)]3+ e NCp7 "full" ZnF, dando suporte à hipótese de ejeção não-covalenteAbstract: Many complementary approaches have been used to inactivate the NCp7 zinc fingers for therapeutic use. The cysteine residues on the HIV-1 nucleocapsid protein (NCp7) are some of the most nucleophilic of all zinc-bound thiolates in proteins. Electron-rich metals such as Au(I) are particularly suitable for designing metal-based zinc ejectors because as thiophilic Lewis acid electrophiles they have high affinity for Cys residues. Without the proper tridimensional folding, NCp7 is inactivated and unable to further recognize specific nucleic acid sequences. A series of Au(I) complexes with the general structure [Au(L)(PR3)] (R=Et or Cy) was designed. The two aromatic residues in the structure of NCp7 (Phe16 and Trp37) are responsible for ?-stacking with purine and pyrimidine residues on RNA and DNA and, for introducing and extra selectivity component to the designed compounds, an aromatic L ligand was compared to the labile Cl. We also examined for comparison the `standard" gold-phosphine compound auranofin which contains a sugar moiety coordinated to the {Au(PEt3)} moiety. Both the nature of the phosphine and the nature of L affect reactivity with the C-terminal NCp7 F2 and the `full" NC, and both factors play important roles on determining the the final coordination sphere of Au once incorporated into the protein. The first step is the electrophilic attack of the Au(I)-phosphine compounds on the Zn-coordinated residues, forming an heterobimetallic {R3PAu}-ZnF species. Two alternative pathways open up from here on. In the most typical pathway, following Zn ejection the {R3PAu} moiety can remain coordinated to a Cys residue and, after loss of the phosphine, lead to Cys-Au-Cys gold finger (AuF). Compounds with slower reactivity such as [Au(dmap)(Et3P)] allow us to probe the initial stages of this mechanism, with species as such as {Et3PAu}-apoNCp7 still being present. Using longer incubation times or using more reactive compounds such as the chloride precursors provides information on the final species, the gold finger itself. In an alternative pathway, observed for the model compound auranofin, the {R3PAu} moiety coordinates to a His residue, and the final hypothetical AuF obtained from this pathway has Cys-Au-His coordination sphere. Although Au(III) is not very stable under biological conditions due to its high reduction potential and fast ligand exchange rates, many recent Au(III)-containing compounds have been rationally designed by tailoring the ligands to stabilize Au(III). The Au(III) compounds evaluated so far as ZnF inhibitors often undergo reduction to Au(I) with loss of all ligands, thus it is commonly accepted that the oxidation state of incorporated gold from a variety of complexes in {AuF} is +1. By handpicking the ligands, it is possible to fine tube the stability of Au(III) complexes, stabilizing the Au(III) oxidation state, even in the presence of peptides with high cysteine content such as ZnFs. Here we explored the Au(III)(C^N) motif based on the organometallic compound [Au(2-bnpy)Cl2] (2-bnpy = deprotonated 2-benzylpyridine) in comparison to a series of Au(III) complexes with typical bidentate ?2N,N? chelators (2,2¿-bipyridine, 4,4¿-dimethyl-2,2¿-bipyridine and 1,10-phenanthroline). The organometallic compound Au(2-bnpy)Cl2 had a sui generis mechanism of zinc ejection, never reported before for any metal compound, which consists on the transfer of the 2-bnpy ligand to a Cys residue from the protein, leading to the formation a C-S bond. Determining the actual coordination sphere of Au in the AuF obtained by interacting Au(I) and Au(III) complexes with ZnF proteins is an interesting challenge, and for that purpose we used two innovative approaches for obtaining structural information in solution. Travelling-Wave Ion Mobility (TWIM) coupled to Mass Spectrometry (MS) was used to evaluate the interaction of the Au(I) compound [AuCl(Et3P)] with two model ZnF proteins that differ on the Zn coordination sphere: NCp7 ZnF2 (Cys3His) and also third finger of the human transcription factor Sp1 (Cys2His2). Furthermore, X-Ray Absorption Spectroscopy (XAS) was used in a "dual-probe" approach to monitor oxidation state, coordination sphere changes and geometry changes of both Au and Zn for the interaction of two series of compounds. In the first series, two Au(I) compounds ([AuCl(Et¬3P)] and auranofin) were compared when interacting with two ZnF targets, NCp7 ZnF2 and Sp1 ZnF3. TWIM-MS and XAS data indicate that [AuCl(Et3P)] leads to the formation of a Cys-Au-His AuF when interacting with Sp1 ZnF3, as opposed to the Cys-Au-Cys AuF identified when interacting with NCp7 ZnF2. Finally, XAS was used to compare the interaction of two [Au(dien)L]n+ compounds (dien = diethylenetriamine; L = Cl, n= 2; L=dmap, n=3) with the same two zinc fingers and demonstrated that [Au(dien)(dmap)]3+ retains the AuN4 coordination sphere and square planar geometry around Au(III), suggesting that either the compound remains unreacted or it behaves as a non-covalant Zn ejector. MS data confirmed the existence of Zn ejection, and the identification of a non-covalent adduct between [Au(dien)(dmap)]3+ and NCp7 "full" ZnF supported the non-covalent ejector hypothesisDoutoradoQuimica InorganicaDoutor em Ciências140466/2014-2CNP

Bioinorganic applications of gold and platinum coordination compounds: a brief historical overview and recent advances in 2017

oai:ojs.journalamb.com:article/5Gold-based metallodrugs have been used for a wide variety of medical–related applications. Although none of them have reached clinical trials, many compounds show potential for a plethora of possible applications. Platinum compounds, on the other hand, are the leading class of metallodrugs used for the treatment of cancer, with successful representatives worldwide, such as cisplatin, carboplatin and oxaliplatin. In this minireview, we will briefly present the development of metallodrugs based on such metals throughout the year of 2017

Synthesis and crystal structure of di­chlorido­(1,10-phenanthroline-κ2N,N′)gold(III) hexa­fluorido­phosphate

FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOA gold(III) salt of composition [AuCl2(C12H8N2)]PF6 was prepared and characterized by elemental and mass spectrometric analysis (ESI(+)–QTOF–MS), 1H nuclear magnetic resonance measurements and by single-crystal X-ray diffraction. The square-planar coordin73710481051FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO2015/25114-42015/20882-3140466/2014-2The authors are grateful to Dr Déborah de Alencar Simoni, technician of the Institutional Single Crystal XRD facility – UNICAMP, Brazil, for the data collection and preliminary data refinement

X-ray Absorption Spectroscopy Combined with Time-Dependent Density Functional Theory Elucidates Differential Substitution Pathways of Au(I) and Au(III) with Zinc Fingers

A combination of two elements’ (Au, Zn) X-ray absorption spectroscopy (XAS) and time-dependent density functional theory (TD-DFT) allowed the elucidation of differential substitution pathways of Au(I) and Au(III) compounds reacting with biologically relevant zinc fingers (ZnFs). Gold L3-edge XAS probed the interaction of gold and the C-terminal Cys2HisCys finger of the HIV-1 nucleocapsid protein NCp7, and the Cys2His2 human transcription factor Sp1. The use of model compounds helped assign oxidation states and the identity of the gold-bound ligands. The computational studies accurately reproduced the experimental XAS spectra and allowed the proposition of structural models for the interaction products at early time points. The direct electrophilic attack on the ZnF by the highly thiophilic Au(I) resulted in a linear P–Au–Cys coordination sphere after zinc ejection whereas for the Sp1, loss of PEt3 results in linear Cys–Au–Cys or Cys–Au–His arrangements. Reactions with Au(III) compounds, on the other hand, showed multiple binding modes. Prompt reaction between [AuCl(dien)]2+ and [Au(dien)(DMAP)]3+ with Sp1 showed a partially reduced Au center and a final linear His–Au–His coordination. Differently, in the presence of NCp7, [AuCl(dien)]2+ readily reduces to Au(I) and changes from square-planar to linear geometry with Cys–Au–His coordination, while [Au(dien)(DMAP)]3+ initially maintains its Au(III) oxidation state and square-planar geometry and the same first coordination sphere. The latter is the first observation of a “noncovalent” interaction of a Au(III) complex with a zinc finger and confirms early hypotheses that stabilization of Au(III) occurs with N-donor ligands. Modification of the zinc coordination sphere, suggesting full or partial zinc ejection, is observed in all cases, and for [Au(dien)(DMAP)]3+ this represents a novel mechanism for nucleocapsid inactivation. The combination of XAS and TD-DFT presents the first direct experimental observation that not only compound reactivity, but also ZnF core specificity, can be modulated on the basis of the coordination sphere of Au(III) compounds.This work was supported by National Science Foundation NSF CHE-1413189, and São Paulo Research Foundation (FAPESP) 2013/20334-0 and 2015/9905-1, Brazilian Federal Agency, for the Support and Evaluation of Graduate Education (CAPES), CAPES/PVES 154/2012 and 0580/2013. We thank the Brazilian Synchrotron Light Laboratory for the beamtime and the XAFS1 and XAFS2 staff for the support. We especially thank Anna Paula Sotero and Carlos Doro Neto for the technical support at the synchrotron beamlines. F.A.L. acknowledges the National Council for Scientific and Technological Development (CNPq) for the productivity grant 311270/2015-8″. C.A. acknowledges support from FAPESP 2013/20334-0 and Brazilian Synchrotron Light Laboratory LNLS 1-XAFS1-17707 and LNLS2 research project 2015 0089. R.B. acknowledges support from the Icelandic Research Fund, Grant No. 141218051, and the University of Iceland Research Fund

Metal complexes with nimesulide : synthesis, characterization and applications in bioinorganic medicinal chemistry

Orientador: Pedro Paulo CorbiDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de QuímicaResumo: Complexos metálicos têm sido estudados quanto as suas propriedades medicinais há décadas. Neste trabalho, dois complexos inéditos de Ag(I) e Pt(II) foram sintetizados com o anti-inflamatório nimesulida (NMS), e avaliados como agentes antibacterianos e antitumorais. O complexo Ag-NMS (AgC13H11N2O5S) apresenta o ligante em uma coordenação bidentada à prata pelos átomos de N e O do grupo sulfonamida. A estrutura proposta foi confirmada por DFT. Devido à baixa solubilidade em água, foi preparado um complexo de inclusão de Ag-NMS em b-CD, pelo método de co-evaporação. Utilizando o método de Scatchard, foi determinado o valor de Ka = 370 2 L mol. Estudos de RMN por correlação H-H através do espaço mostram que a inclusão ocorre pelo grupo fenoxi da NMS. Já o complexo Pt-NMS (PtC26H22N4O10S2) apresenta dois ligantes, coordenados pelos átomos de N e O do grupo sulfonamida, para cada Pt(II). A DFT indica que o isômero N, O trans é o mais estável. O complexo Ag-NMS apresentou valores de MIC na faixa de 15,0-120 mmol L sobre cepas de Pseudomonas aeruginosa, Escherichia col e Staphylococcus aureus. O CE-[(Ag-NMS)·b-CD], embora mais solúvel em água do que o Ag-NMS, não apresentou atividade antibacteriana nas concentrações testadas. Os complexos Ag-NMS e Pt-NMS mostraram-se citotóxicos sobre células normais (Balb/c 3T3) e tumorais (SK-Mel 103 e Panc-1), porém o Pt-NMS foi significativamente mais seletivo contra as linhagens tumorais. Os ensaios de intercalação com EtBr e a avaliação da estrutura do DNA por dicroísmo circular indicam que o DNA não é um alvo biológico para o complexo Pt-NMS, indicando um mecanismo de ação diferente da cisplatinaAbstract: Metal complexes have been studied regarding its medicinal properties for decades. In this work, novel complexes of Ag(I) and Pt(II) with the anti-inflammatory nimesulide were synthesized and evaluated regarding their antibacterial and antitumoral properties. The Ag-NMS complex (AgC13H11N2O5S) shows the ligand in a bidentate coordination mode, bound to silver through the N and O atoms of the sulfonamide group. The proposed structure was confirmed by DFT. Due to its poor solubility in water, the Ag-NMS complex was included in b-CD, by co-evaporation. The Ka = 370 2 L mol was determined using the Scatchard method. Studies by H-H NMR correlation through space shows the inclusion of NMS by the fenoxi group. The Pt-NMS complex (PtC26H22N4O10S2) contain two ligands, coordinated through the N and O atoms of the sulfonamide group, for each Pt(II). DFT studies indicate that the N,O trans isomer is the most stable. The Ag-NMS complex presents MIC values in the range 15.0-120 mmol L over Pseudomonas aeruginosa, Escherichia coli e Staphylococcus aureus. The inclusion complex CE-[(Ag-NMS)·b-CD], although more soluble in water than Ag-NMS, shows no antibacterial activity in the tested concentrations. Both complexes were cytotoxic against normal (Balb/c 3T3) and tumor (SK-Mel 103 and Panc-1) cells, but the Pt-NMS complex was significantly more selective against tumor cells. The EtBr competitive intercalation assay and the evaluation of CT-DNA structure using circular dichroism show that DNA is not a biological target for the Pt-NMS complex, indicating a mechanism of action different of the cisplatin oneMestradoQuimica InorganicaMestre em Químic

Synthesis and crystal structure of dichlorido(1,10-phenanthroline-κ2N,N′)gold(III) hexafluoridophosphate

A gold(III) salt of composition [AuCl2(C12H8N2)]PF6 was prepared and characterized by elemental and mass spectrometric analysis (ESI(+)–QTOF–MS), 1H nuclear magnetic resonance measurements and by single-crystal X-ray diffraction. The square-planar coordination sphere of AuIII comprises the bidentate 1,10-phenanthroline ligand and two chloride ions, with the AuIII ion only slightly shifted from the least-squares plane of the ligating atoms (r.m.s. = 0.018 Å). In contrast to two other previously reported AuIII-phenantroline structures that are stabilized by interactions involving the chlorido ligands, the packing of the title compound does not present these features. Instead, the hexafluoridophosphate counter-ion gives rise to anion...π interactions that are a crucial factor for the crystal packing

Silver complexes with sulfathiazole and sulfamethoxazole: synthesis, spectroscopic characterization, crystal structure and antibacterial assays

The present work describes the synthesis and spectroscopic characterization of two silver(I) complexes with the sulfonamides sulfathiazole (AgC9H8N3O2S2, Ag-SFT) and sulfamethoxazole (AgC10H10N3O3S, Ag-SFM). Elemental analyses indicate a 1:1 metal/ligand composition for both complexes. Spectroscopic techniques such as 1H, 15N NMR and IR evidence the coordination of both ligands to silver through the nitrogen atom of the sulfonamide group, and also indicate the participation of the 5-membered N-heterocyclic ring in the coordination. The Ag-SFT crystal structure was solved by X-ray powder diffraction and indicates the formation of a dimeric structure with silver bridging between two ligand molecules. Biological studies showed the antibacterial activity of Ag-SFT and Ag-SFM complexes against Gram-positive and Gram-negative bacterial strains, with MIC values ranging from 3.45 to 6.90 mmol L-1 for the sulfathiazole complex and 1.74 to 13.9 mmol L-1 for the sulfamethoxazole complex. The complexes have shown to be more active against Gram-negative bacterial strains.The present work describes the synthesis and spectroscopic characterization of two silver(I) complexes with the sulfonamides sulfathiazole (AgC9H8N3O2S2, Ag-SFT) and sulfamethoxazole (AgC10H10N3O3S, Ag-SFM). Elemental analyses indicate a 1:1 metal/ligand85437444FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPEMIG - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE MINAS GERAIS2012/08230-2240094/2012-3CEX-APQ-00525/14Klasen, H.J., (2000) Burns, 26, p. 117Atiyeh, B.S., Costagliola, M., Hayek, S.N., Dibo, S.A., (2007) Burns, 33, p. 139Modak, S.M., Fox, C.L., Jr., (1973) Biochem. Pharmacol., 22, p. 2391Solioz, M., Odermatt, A., (1995) J. Biol. Chem., 270, p. 9217Hindi, K.M., Ditto, A.J., Panzner, M.J., Medvetz, D.A., Han, D.S., Hovis, C.E., Hilliard, J.K., Youngs, W.J., (2009) Biomaterials, 30, p. 3771Greenhalgh, D.G., (2009) Clin. 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Acta, Part A, 64, p. 418Abbehausen, C., Castro, J.F., Spera, M.B.M., Heinrich, T.A., Costa-Neto, C.M., Lustri, W.R., Formiga, A.L.B., Corbi, P.P., (2011) Polyhedron, 30, p. 2354Erol, S., Altoparlak, U., Akcay, M.N., Celebi, F., Parlak, M., (2004) Burns, 30, p. 357De Paiva, R.E.F., Abbehausen, C., Bergamini, F.R.G., Thompson, A.L., Alves, D.A., Lancellotti, M., Corbi, P.P., (2014) J. Incl. Phenom. Macrocycl. Chem., 79, p. 225Hamilton-Miller, J.M.T., Shah, S., Smith, C., (1993) Chemotherapy, 39, p. 405This study was supported by grants from FAPESP (Fundação de Amparo à Pesquisa do Estado de São Paulo, proc. no. 2012/08230-2), CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico, proc. no. 240094/2012-3) and FAPEMIG (Fundação de Amparo

N,N′,N′′ versus N,N′,O imine-containing coordination motifs: ligand-directed synthesis of mononuclear and binuclear cuII compounds

CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOIt is demonstrated here that tridentate imine ligands can control the nuclearity of copper(II) complexes based on the donor atoms present in the ligand. The N,N′,N′′-donating imine ligand led to a mononuclear compound, namely di­chlorido­[N,N-dimethyl-N′-731015631567CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO140466/2014-2140707/2013-12015/ 25114-42015/20882-3The authors are grateful to Dr Déborah de Alencar Simoni, technician of the Institutional Single-Crystal XRD Facility, UNICAMP, Brazil, for the data collectio

N,N′,N′′ versus N,N′,O imine-containing coordination motifs: ligand-directed synthesis of mononuclear and binuclear CuII compounds

It is demonstrated here that tridentate imine ligands can control the nuclearity of copper(II) complexes based on the donor atoms present in the ligand. The N,N′,N′′-donating imine ligand led to a mononuclear compound, namely dichlorido[N,N-dimethyl-N′-(pyridin-2-ylmethylidene)ethane-1,2-diamine]copper(II) monohydrate, [CuCl2(C10H15N3)]·H2O, 1, while the N,N′,O-donating imine ligand produced a binuclear metal complex, namely μ2-chlorido-dichlorido(μ2-2-{[2-(dimethylamino)ethyl]iminomethyl}phenolato)(N,N-dimethylethylenediamine)dicopper(II) 0.11-hydrate, [Cu2(C11H15N2O)Cl3(C4H12N2)]·0.11H2O, 2. The structure of 2 is a remarkable example of a binuclear copper(II) complex containing a single substituted 2-iminomethylphenolate ligand that has two copper(II) sites in square-pyramidal coordination