A series of CoIII complexes [Co(RImP)2][PF6], with HMeImP = 1,1'-(1,3-phenylene)bis(3-methyl-1-imidazole-2-ylidene)) and R Me, Et, iPr, nBu, is presented in this work. The influence the strong donor ligand on ground excited-state photophysical properties was investigated context different alkyl substituents at imidazole nitrogen. X-ray diffraction revealed no significant alterations structures all differences emerge from electronic structures. These were probed via cyclic voltammetry UV-vis...

Four homo- and heteroleptic complexes bearing both polypyridyl units N-heterocyclic carbene (NHC) donor functions are studied as potential noble metal-free photosensitizers. The [FeII(L1)(terpy)][PF6]2, [FeII(L2)2][PF6]2, [FeII(L1)(L3)][PF6]2, [FeII(L3)2][PF6]2 (terpy = 2,2′:6′,2″ terpyridine, L1 2,6-bis[3-(2,6-diisopropylphenyl)imidazol-2-ylidene]pyridine, L2 2,6-bis[3-isopropylimidazol-2-ylidene]pyridine, L3 1-(2,2′-bipyridyl)-3-methylimidazol-2-ylidene) contain tridentate ligands of the...

Abstract A series of bis‐guanidine ligands designed for use in biomimetic coordination chemistry has been extended to a library matrix combining unprecedented substitutional flexibility within the guanidyl residues with wide range aliphatic and aromatic spacers connecting these functionalities. The underlying protocol can be used predefined ureas as well secondary amines build up units by reaction phosgene if are otherwise unavailable. In latter case, resulting urea intermediates do not have...

One to two and back again: A disulfide–thiolate interconversion process in a dinuclear copper complex is induced by chloride ions (see scheme). Within this compound, the coordinating atoms serve either as electron source or sink thus oscillate between oxidation states +I +II. Detailed facts of importance specialist readers are published "Supporting Information". Such documents peer-reviewed, but not copy-edited typeset. They made available submitted authors. Please note: The publisher...

For the first time, potential of noble‐metal‐free iron‐based photosensitizers for photocatalytic water reduction by using homo‐ and heteroleptic carbene complexes was proven. The development a facile synthesis route such delineated. were investigated UV/Vis fluorescence spectroscopy, DFT calculations, cyclic voltammetry, X‐ray absorption spectroscopy. Their catalytic performance compared to that established noble‐metal‐containing as [Ir(ppy) 2 (bpy)][PF 6 ] (Hppy = 2‐phenylpyridine, bpy...

The central role of cupric superoxide intermediates proposed in hormone and neurotransmitter biosynthesis by noncoupled binuclear copper monooxygenases like dopamine-β-monooxygenase has drawn significant attention to the unusual methionine ligation CuM ("CuB") active site characteristic this class enzymes. copper-sulfur interaction proven critical for turnover, raising still-unresolved questions concerning Nature's selection an oxidizable Met residue facilitate C-H oxygenation. We describe...

A new chelating mesoionic carbene ligand, derived from 1,2,3-triazoles, with two redox-active <italic>tert</italic>-butyl-phenolate linkers has been synthesized and explored towards its reactivity electrochemical properties in early transition metal chemistry.

Two closely related FeII complexes with 2,6-bis(1-ethyl-1H-1,2,3-triazol-4yl)pyridine and 2,6-bis(1,2,3-triazol-5-ylidene)pyridine ligands are presented to gain new insights into the photophysics of bis(tridentate) iron(ii) complexes. The [Fe(N^N^N)2]2+ pseudoisomer sensitizes singlet oxygen through a MC state nanosecond lifetime after MLCT excitation, while [Fe(C^N^C)2]2+ possesses similar 3MLCT as tris(bidentate) [Fe(C^C)2(N^N)]2+ four mesoionic carbenes.

A mixed-valent redox-active copper thiolate complex is formed in the reaction of [Cu(MeCN)4]PF6 with a CPh3 thioether by combination homo- and heterolytic cleavage SCPh3 bond. In its oxidized state, hexanuclear sulfur cluster (see picture) has same average metal oxidation state as dinuclear center cytochrome c oxidase or N2O reductase. Detailed facts importance to specialist readers are published "Supporting Information". Such documents peer-reviewed, but not copy-edited typeset. They made...

Abstract A Systematic Study on the Coordination Properties of Guanidine Ligand N 1 ,N 2 ‐Bis(1,3‐dimethylimidazolidin‐2‐ylidene)‐ethane‐1,2‐diamine with Metals Mn, Co, Ni, Ag and Cu The syntheses characterization compounds [Mn(DMEG e)Cl ] ( ), [Co(DMEG [Ni(DMEG e) ]I 3 [Cu(DMEG e)I] 4 ) {[Ag(DMEG e)]BF } n 5 bisguanidine ligand ‐bis(1,3‐dimethylimidazolidin‐2‐ylidene)ethane‐1,2‐diamine (DMEG are described. All complexes synthesized by reaction corresponding metal salt DMEG e in MeCN or THF....

Perylene derivatives with a unilaterally and bilaterally extended core show luminescence in the visible wavelength range (500–600 nm) that can be excited by absorption ultraviolet (360–370 nm). This unusual behavior is investigated means of excitation spectroscopy, cyclic voltammetry, calculations based on (time-dependent) density functional theory. The results indicate compounds promising features for optoelectronic applications even might used as fluorescent dyes lasing. supported...

Heteroleptic iron based complexes bearing the 2,6‐bis[3‐(2,6‐diisopropylphenyl)imidazol‐2‐ylidene]pyridine motif and a polypridine ligand have been synthesized characterized in their ground excited state. This series of includes first example hetero‐bimetallic complex connecting an N ‐heterocyclic carbene photosensitizer with cobalt dimethylglyoxime fragment. Focus is set on influence linker center as second at photophysics. While electronic absorption spectroscopy cyclic voltammetry reveal...

Verblüffende Umwandlung: Ein reversibler Disulfid-Thiolat-Umwandlungsprozess in einem zweikernigen Kupferkomplex wird durch Chloridionen induziert. Als Elektronenquelle und -senke dienen hierbei die koordinierenden Kupferatome, zwischen den Oxidationsstufen +I +II hin her pendeln können.

An imidazolinium-dithiocarboxylate betaine has been applied for the first time as a ligand in coordination polymer with copper(<sc>i</sc>) halides.

In search of new ligand motifs for photoactive iron(II) complexes with long-lived MLCT states, a series six tridentate amine-functionalized bis-n-heterocyclic carbene (NHC)-pyridine ligands is presented. the homoleptic imidazole-, methylimidazole-, or benzimidazole-2-ylidene, NHC donors are employed in combination pyridine, functionalized 4-position by dimethylamine dibenzylamine. The effects these different functionalities on electronic structure examined through detailed ground state...

Abstract The transition metal complexes with the ligand 1,3‐bis( N , N′ ‐tetramethylguanidino)propane (btmgp), [Mn(btmgp)Br 2 ] ( 1 ), [Co(btmgp)Cl [Ni(btmgp)I 3 [Zn(btmgp)Cl 4 [Zn(btmgp)(O CCH ) 5 [Cd(btmgp)Cl 6 [Hg(btmgp)Cl 7 and [Ag (btmgp) ][ClO ·2MeCN 8 were prepared characterised for first time. stoichiometric reaction of corresponding water‐free salts btmgp in dry MeCN or THF resulted straightforward formation mononuclear – binuclear complex . In M II ion shows a distorted tetrahedral...

Ein redoxaktiver gemischtvalenter Kupfer-Thiolat-Komplex entsteht bei der Reaktion von [Cu(MeCN)4]PF6 mit einem CPh3-Thioether durch ein Zusammenwirken homo- und heterolytischer Spaltung S-CPh3-Bindung. Die Metallatome in dem sechskernigen Kupfer-Schwefel-Cluster (siehe Bild) haben im oxidierten Zustand dieselbe mittlere Oxidationsstufe wie zweikernigen Kupfer-Thiolat-Zentrum (CuA) Cytochrom-c-Oxidase N2O-Reduktase.

We present the synthesis of a series new lanthanide(III) complexes supported by monoanionic bidentate anilidophosphine ligand (N-(2-(diisopropylphosphanyl)-4-methylphenyl)-2,4,6-trimethylanilide, short PN-). The work comprises characterization variety heteroleptic containing either one or two PN ligands as well study on further functionalization possibilities. cover selected examples over whole including lanthanum, cerium, neodymium, gadolinium, terbium, dysprosium, and lutetium. In case...

A new base metal iron-cobalt dyad has been obtained by connection between a heteroleptic tetra-NHC iron(II) photosensitizer combining 2,6-bis[3-(2,6-diisopropylphenyl)imidazol-2-ylidene]pyridine with 2,6-bis(3-methyl-imidazol-2-ylidene)-4,4'-bipyridine ligand, and cobaloxime catalyst. This novel iron(II)-cobalt(III) assembly extensively characterized ground- excited-state methods like X-ray crystallography, absorption spectroscopy, (spectro-)electrochemistry, steady-state time-resolved...

As a contribution to better understanding of the coordination properties imidazolinium–dithiocarboxylate ligands towards copper, first route oligonuclear copper–betaine complexes has been developed. Treatment polymer [CuCl(Bz 2 ImCS )] n ( 1 ) suspended in acetonitrile with thallium(I) hexafluorophosphate different ratios affords discrete copper(I) cluster cations [Cu 4 (Bz Cl ] 2+ and 3 5 3+ ). Single‐crystal X‐ray diffraction (PF 6 · 2MeCN Et O reveals occurrence unique copper–sulfur...

Abstract Syntheses and Structures of the First Polynuclear Manganese Guanidine Complexes Containing Mono‐Protonated Bis‐Guanidine Ligands Metallation two differently alkylated bis‐guanidine ligands containing a central pyridine functionality, namely N 2 ,N 6 ‐bis(1,3‐dimethylimidazolidin‐2‐ylidene)pyridine‐2,6‐diamine (DMEG py {N 7 C 15 H 23 }, L 1 ) ‐bis(1,1,3,3‐tetramethyl‐guanidine)pyridine‐2,6‐diamine (TMG 27 ), with manganese(II) bromide chloride leads to formation novel complexes [MnBr...

Abstract The copper(I) and copper(II) complexes [Cu((TMG et ) 2 N SEt)]BPh 4 ( 1· BPh SEt)Cl]Cl 2· Cl) with (TMG SEt = ((Me N) C=NCH CH NCH were synthesized structurally characterized as a model system for the copper enzyme PHM, monooxygenase involved in activation of peptide hormones neuropeptides. reaction complex dioxygen has been studied using low temperature stopped‐flow methods. However, contrast to PHM no formation an end‐on superoxido could be observed. Instead equilibrium between...

The novel chiral cyclopentadiene-type ligand CpCH is accessible from dibenzosuberenone in a five-step sequence with overall yields of 64%. NMR spectroscopy as well DFT calculations prove that the racemization this compound slow at room temperature. By deprotonation and subsequent reaction appropriate iron(II) precursors, ferrocene derivatives (CpC)2Fe (CpC)Fe(4Cp) are good yields. latter could structurally be characterized by means single-crystal X-ray crystallography. Mössbauer proves...

Creation of a novel chelating site by roll-over cyclometallation opens up new strategy for rapid access to heterobimetallic complexes. Combinations iridium(<sc>iii</sc>) with palladium(<sc>ii</sc>) or platinum(<sc>ii</sc>) have exemplarily been synthesized.