The coordination modes of the ligand 2,5,8-trithia[9](2,6)pyridinophane (L) to thallium(i), gold(iii) and gold(i) have been studied. Thallium(i) is coordinated by the macrocyclic ligand in [Tl(L)](PF6) (1) through all the sulfur and nitrogen atoms, in a distorted square-pyramidal geometry with the thallium(i) ion in the apical position and with the presence of an inert lone pair. Gold(iii) is bonded by the ligand only through the nitrogen of the pyridine group in [AuCl3(L)] (2), whereas two AuI-C6F5 fragments coordinate the sulfur atoms next to the pyridine moiety of the ligand in [{Au(C6F5)}2(μ-L)] (3), which form a linear polymer through intermolecular aurophilic contacts. The heterometallic TlI/AuI complex {[Au(C6F5)2Tl]2(L)}n (4) features a polymeric structural nature with a metallic pseudo-rhombic Au2Tl2 core, which repeats itself forming a zig-zag polymer. In each Au2Tl2 unit only one thallium atom is bonded by the NS3 donor set of the macrocyclic ligand and also forms two unsupported Au-Tl bonds with two [Au(C6F5)2]- units in an overall pseudo-octahedral geometry. The other thallium atom similarly bridges the same [Au(C6F5)2]- units and links a neighbouring Au2Tl2 moiety, thus exhibiting a distorted trigonal planar geometry being bonded only to three gold atoms with unsupported Au-Tl interactions. This complex displays an interesting thermochromic behaviour showing emissions mainly resulting from MM'CT transitions at room temperature. At 77 K a dual emission appears, probably arising from the two different thallium environments. DFT calculations have been carried out in the attempt to investigate the origin of the emissions of complex 4.

PMMA composites and solids of complexes of formulas [AgX(P-P)]n [n = 1 and 2; X = Cl, NO3, ClO4, CF3COO, and OTf; P-P = dppb, xantphos, (PR2)2C2B10H10 (R = Ph and iPr)] display the whole palette of colors from blue to red upon selection of the anionic ligand (X) and the diphosphane (P-P). The diphosphane seems to play the most important role in tuning the emission energy and thermally activated delayed fluorescence (TADF) behavior. The PMMA composites of the complexes exhibit higher quantum yields than that of the diphosphane ligands and those with dppb are between 28 and 53%. Remarkably, instead of blue-green emissions which dominate the luminescence of silver diphosphane complexes in rigid phases, those with carborane diphosphanes are yellow-orange or orange-red emitters. Theoretical studies have been carried out for complexes with P-P = dppb, X = Cl; P-P = dppic, X = NO3; P-P = dppcc, X = Cl, NO3, and OTf and the mononuclear complexes [AgX(xantphos)] (X = Cl, Br). Optimization of the first excited triplet state was only possible for [AgX(xantphos)] (X = Cl and Br). A mixed MLCT and MC nature could be attributed to the S0 → T1 transition in these three-coordinated complexes.

A series of gold(I) and gold(III) N-acyclic diamino carbene (ADC) complexes with different ancillary ligands have been synthesized. The chloride carbene derivatives [Au{C(NHR)(NHCH(2)py)}Cl] (R = Cy, R = naphthyl, R = xylyl) have been obtained by reaction of 2-picolylamine with the corresponding [AuCl(CNR)]. The gold(I) thiolate derivatives [Au{C(NHR)(NHCH(2)py)}(Spy)] were prepared by reaction of the chlorido complexes with 2-mercaptopyridine (2-HSpy) in presence of potassium carbonate. The phosphane derivative [Au(pyCH(2)NH(2))(PPh3)](OTf) was obtained by reaction of freshly prepared [Au(OTf)(PPh3)] with 2-picolylamine. The phosphane-carbene complexes [Au{C(NHR)(NHCH(2)py}(PPh3)](OTf) were obtained from the reaction of picolylamino species with the isocyanide. The gold(III) derivative cis-[Au(C6F5)(2)(pyCH(2)NH(2))](ClO4) was obtained by the reaction of 2-picolylamine with freshly [Au(C6F5)(2)(Et2O)(2)](ClO4). The reaction of the former with CNCy led to complex cis-[Au(C6F5)(2){C(NHCy)(NHCH(2)py)}]ClO4 by a nucleophilic attack of the isocyanide to the amine ligand, thus producing a bidentate C,N acyclic carbene ligand. Cytotoxic studies against the tumor human cell lines Jurkat (T-cell leukaemia), MiaPaca2 (pancreatic carcinoma), A549 (lung carcinoma) and MDA-MB-231 (breast carcinoma) showed moderate to good cytotoxic activity for some of the complexes.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

This work encompasses a comprehensive study of host–guest interactions between cyclic trimer metal–carborane [Au 3 (1,2‐C 2 B 10 H 10 ) 3 ] 3– and several guest species such as cations (H + , Li + , Be 2+ , Hg 2+ ), anions (F – , H – , Cl – , Br – , I – , HCC – ), and neutral molecules (H 2 , CO 2 , I 2 , HCCH, N 2 ). A computational study has been carried out to evaluate energetic profiles and determine the contribution of attractive or repulsive interactions between guest and host. The energy minima obtained call our attention to several cases. For instance, all above cations form stable minima as guest complexes with the three gold atoms of the host. Unexpectedly, pyramidal H – or F – species are obtained as energy minima, while other anions give completely repulsive interactions. Finally, the CO 2 molecule is also trapped inside the trinuclear ring.

The Cover Feature shows the interaction pattern between a triangular gold–carborane cluster trianion (host) and various cations, neutral molecules, and anions (guests). The funnel above the cluster indicates that some of the guests, regardless of their charge or size, can be trapped inside the void of the host. Cations form stable complexes according to the large electrostatic potential that favors attractive host···guest adducts, but some neutral and anionic guests can also be enclosed. Unexpectedly, hydride and fluoride are trapped, forming tetraanionic species, but among neutral molecules, only CO2 is trapped. More information can be found in the Full Paper by J. M. Oliva-Enrich et al.

By reaction of 2-aminofluorene with 2-pyridinecarboxaldehyde a new Schiff base (L) is obtained. The reaction of this ligand with Ag(I) and Cu(I) salts in different stoichiometry leads to the complexes [Ag(CF3SO3 )(L)PPh3] (1) or [ML2]A (M = Ag, Cu; A = CF3SO3, ClO4 or BF4). Structural characterization by X-ray crystallography has been carried out for complexes [AgL2]ClO4 (4) and [Ag(L)(PPh3)(2)] (CF3SO3) (6), which confirms the chelate nature of L and the presence of Ag center dot center dot center dot H interactions between two molecules. The biological studies show that Schiff base L presents antibacterial activity in Gram-positive bacteria and E. coli. The coordination to silver increases this activity, but the formation of the copper complex does not generate significant changes.

A new phosphine ligand bearing a thiophene moiety, C4H3SNHCOCH2CH2PPh2 (L), has been prepared by reaction of the aminophosphine Ph2PCH2CH2NH2 with thiophenecarbonylchloride in the presence of triethylamine. The coordination behavior towards gold(I), gold(III) and silver(I) species has been studied and several metal compounds of different stoichiometry have been achieved, such as [AuL2]OTf, [AuXL] (X = Cl, C6F5), [Au(C6F5)3L], [AgL2]OTf or [Ag(OTf)L]. Additionally, the reactivity of the chloride gold(I) species with biologically relevant thiolates was explored, thus obtaining the neutral thiolate compounds [AuL(SR)] (SR = 2-thiocitosine, 2-thiolpyridine, 2-thiouracil, 2-thionicotinic acid, 2,3,4,6-tetra-6-acetyl-1-thiol-β-d-glucopyranosato or thiopurine). The antitumor activity of the compounds was measured by the MTT method in several cancer cells and the complexes exhibit excellent cytotoxic activity.

A series of luminescent monometallic [AuL(PPh3)] (1-3) and bimetallic [Au2(μ-dppe)L2] (4, 6, 8) and [Au2(μ-dppp)L2] (5, 7, 9) complexes, where L is either 4-cyano-indole, isatin, or 5,7-dimethyl-isatin, and dppe and dppp are 1,2-bis(diphenylphosphino)ethane and 1,3-bis(diphenylphosphino)propane, respectively, have been synthesised. X-ray diffraction confirmed the tendency to establish aurophillic interations for those complexes containing dppe. Luminescence studies and theoretical calculations revealed a different origin for both families, i.e. indole and isatin species. Thus, indole derivatives presented a ligand-to-ligand-charge-transfer transition (LLCT) from the indole to the PPh3 fragment, whereas for the isatin derivatives an intraligand-charge-transfer transition (ILCT) within the isatin fragment is proposed. In both cases, the gold centre was slightly implicated as a ligand-to-metal-charge transfer transition (LMCT) (from the indole/isatin to Au(i)). Cell antiproliferative assays in lung cancer cells (A549), leukemia Jurkat-pLVTHM and Jurkat-shBak cells (cisplatin sensitive and resistant, respectively) showed excellent cytotoxic values (10.11-0.28 μM), showing the leukemia cells to be the most sensitive and the bimetallic species to be the most active agents. Preliminary studies associated the cytotoxicity with a combination of different factors, the metallic fragment being mainly responsible. Remarkably, these complexes are able to inhibit the cellular growth of cisplatin resistant Jurkat-shBak cells highlighting their promising future as an alternative anticancer agent.

Two neutral bis(pentafluorophenyl)thiolate gold(III) complexes with the unsymmetrical S^N ligands 2-aminothiophenol or cysteamine have been synthesized and their reactivity has been studied. Homo- and heterodinuclear compounds were obtained by their coordination to gold(I) or silver(I) derivatives through the sulfur atom. Interestingly, a tetranuclear derivative bearing short gold(I)···gold(I) and the more unusual gold(I)···gold(III) interactions has been prepared. These amino-thiolate derivatives can be used as precursors for the synthesis of novel gold(III) acyclic diaminocarbene complexes by reaction with isocyanides CNR. The nucleophilic attack of the amino group to isocyanide molecules affords the synthesis of unprecedented bidentate C^S acyclic diaminocarbene ligands. All of the complexes are air- and moisture-stable at room temperature and have been spectroscopically and structurally characterized.

A family of mixed phosphane/alkynyl gold(I) complexes was prepared by addition of PPh 3 or PPh 2 py to suspensions of the polymeric species [Au(C≡CR) n ] [R = Ph, 2‐pyridyl (py)] and [Au 2 {C≡C(CH 2 ) 3 C≡C}] n . The resulting complexes are luminescent both at room and low temperature, in solution and in the solid state. The emissions are assigned to intraligand transitions associated with the C≡C moieties or related to 3 [σ(Au–P)→π*(C≡Cpy)] transitions. The crystal structure of dinuclear complex [Au 2 {C≡C(CH 2 ) 3 C≡C}(PPh 2 py) 2 ] shows the presence of dimers stabilized by intermolecular aurophilic interactions.

The reactions of two unsymmetrical P^N (L1) and P^P (L2) ferrocene (Fc) ligands towards group 11 metal complexes were studied. Ligand L1 shows different behavior with the three metals. Gold forms mononuclear derivatives with the metal center coordinated to the phosphorus atom, whereas the reactions with silver(I) or copper(I) complexes afford mononuclear or dinuclear compounds in which both donor atoms, phosphorus and nitrogen, are involved in the coordination to the metal center. The reactions of the diphosphine ligand [Fc(CH2PPh2)(PPh2)] (L2) with gold(I), gold(III), silver(I), or copper(I) complexes afford mono‐, di‐, or trinuclear derivatives. Some homo‐ and heterodinuclear compounds were obtained through the reactions of the mononuclear gold(III) complex [Au(C6F5)3{Fc(CH2PPh2)(PPh2)}] (6), in which one of the phosphorus atoms is free, with gold(I), gold(III), and silver(I) deriiivatives. Some of these derivatives were characterized by X‐ray diffraction analysis.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Two new closo‐carborane selenolated ligands, 2‐[(1′‐Me‐1′,2′‐closo‐C2B10H10)SeCH2]C5H4N (L1) and 2,6‐[(1′‐Me‐1′,2′‐closo‐C2B10H10)SeCH2]2C5H3N (L2), were prepared by the C–H activation of 1‐Me‐1,2‐C2B10H11 with nBuLi, followed by the insertion of elemental selenium into the C–Li bond and reaction with 2‐(BrCH2)C5H4N or 2,6‐(BrCH2)2C5H3N, respectively. The closo species L1 and L2 were deboronated with CsF to give the nido‐carborane cesium salts Cs[2‐{(1′‐Me‐1′,2′‐nido‐C2B9H9)SeCH2}C5H4N] (1) and Cs2[2,6‐{(1′‐Me‐1′,2′‐nido‐C2B9H9)SeCH2}2C5H3N] (2). The isolation of the complexes [Ag(OTf)(L2)] (3, OTf = triflate), [Ag(PPh3)(L2)][OTf] (4), [Cu(L2)(MeCN)][PF6] (5), and [Cu(L2)2][PF6] (6) indicates the coordination ability of L2 towards these metals. The molecular structures of L1 and L2 were established by single‐crystal X‐ray diffraction. Quantum‐chemical calculations confirmed the molecular geometries and also the presence of C–H···Se intramolecular interactions as well as C–H···H–B and B–H···π intermolecular interactions.

An unprecedented tetranuclear gold derivative with unusual gold-enyne moieties is prepared by a mild and neat rearrangement of a dinuclear gold complex with a bridging bis(diphenylphosphino)alkyne and terminal alkynyl ligands. The complex originates as a consequence of an intramolecular addition of the AuC[triple bond, length as m-dash]CTol fragment to the internal diphosphine triple bond Ph2PC[triple bond, length as m-dash]CPPh2. The crystal structure of the tetranuclear complex shows a dinuclear metallacycle with a very short AuAu bond interaction and bridging phosphino-enyne ligands. This disposition clearly stabilises the elusive vinyl gold species omnipresent as intermediates in gold-catalysed reactions.

A rational approach to the synthesis of cage-like compounds has been realized to build a new family of sulfido-phosphane Au(i) polynuclear complexes. Ditopic phosphane ligands with an extended aromatic system were used to obtain cage compounds with a clearly determined geometry. Au(i) complexes have been fully characterised in solution using spectroscopy methods, and DFT optimisation of the molecular structure gives additional arguments in favour of the suggested structural patterns. All complexes obtained are luminescent in solution and in the solid state, and display multiple emissions with an unusual combination of two phosphorescence bands and one fluorescence band. DFT calculations show that multiple emissions were mainly determined by 1IL and metal perturbed 3IL transitions. The ratio of singlet and triplet emission components depends on the distance between the ligand chromophoric centre and Au(i).

This cover feature shows the great potential of the ferrocene molecule for a custom-made synthesis of ferrocene ligands, especially asymmetric disubstituted species bearing phosphine ligands and their corresponding group 11 metal complexes. These derivatives may be suitable for application in catalysis. Details are discussed in the article by M. D. Villacampa, M. C. Gimeno et al. on page 247 ff (DOI: 10.1002/ejic.201600929). For more on the story behind the cover research, see the Cover Profile (DOI: 10.1002/ejic.201601554).

Thiophene bioconjugates with methionine or tryptophan methyl esters have been prepared by reaction of chlorocarbonyl thiophene with the corresponding amino acid ester in the presence of NEt3. The coordination behaviour of these new ligands towards Ag(I) and Au(I)/Au(III) complexes has been studied. In the case of the methionine ester conjugate the coordination of the gold or silver fragments takes place through the sulfur atom of the methionine, and for the silver species [Ag(OTf)(PPh3)] coordination as HN<^>S chelate is proposed. For the thiophene-tryptophan ester bioconjugate the reaction with [Au (acac)(PPh(2)py)] (acac = acetylacetonate) results in the substitution of the proton of the cyclic NH groups by the fragment [AuPPh(2)py](+) affording the complex [Au(ThiopheneCOTrpOMe)(PPh(2)py)], whereas the reaction with no basic complexes such as [M(OTf)(PPh3)] (M = Au, Ag) produces coordination of the metal atom to the nitrogen of the indole moiety. Cytotoxicity studies towards several cancer lines such as A-549, Hep-G2 or NIH-3T3 have been performed for the tryptophan derivatives. The thiophene bioconjugate shows no activity whereas the gold and silver complexes exhibit moderate to good activities in two of the cell lines, and only the silver complex is active in the A-549 cell line. (C) 2017 Elsevier B.V. All rights reserved.

Imidazolium-4-carboxylate salts are prepared for the first time via a retro-Claisen reaction of quinone-fused imidazolium salts.

The synthesis and characterization of luminescent gold(III) compounds, obtained by coordination of the metal center to different phosphines, is described. To avoid deactivation of luminescence by the presence of low-energy d-d ligand field states in the gold(III) center, the ligands bonded to the metallic center have been carefully chosen, among which we used bidentate phosphines with different numbers of phenylene or alkynyl-phenylene spacers and pentafluorophenyl groups. The reaction of [Au(C6F5)(3)(tht)] (tht = tetrahydrothiophene) with the corresponding diphosphines gave the complexes [{Au(C6F5)(3)}(2)(1,4PPh(2)(C6H4) nPPh2)] (n = 1-3) and [{Au(C6F5)(3)}(2)(PPh2C equivalent to C(C6H4)(n)C equivalent to CPPh2)] (n = 0-2). The study of their optical behavior, reveals emission color variations from violet to yellow for the compounds containing the phosphines with one, two, and three phenylene spacers, respectively, and much more fine-tuning, from deep blue to brilliant blue for those intercalating alkynyl and phenylene spacers. Four of the new complexes were also characterized by X-ray diffraction crystallography, showing supramolecular structures formed through hydrogen bonding.