Synthesis,Characterization, Self‐Assembly,Gelation, Morphology and Computational Studies of Alkynylgold(III) Complexes of 2,6‐Bis(benzimidazol‐2′‐yl)pyridine Derivatives

A novel class of alkynylgold(III) complexes of the dianionic ligands derived from 2,6‐bis(benzimidazol‐2′‐yl)pyridine (H₂bzimpy) derivatives has been synthesized and characterized. The structure of one of the complexes has also been determined by X‐ray crystallography. Electronic absorption studies showed low‐energy absorption bands at 378–466 nm, which are tentatively assigned as metal‐perturbed π–π* intraligand transitions of the bzimpy^2? ligands. A computational study has been performed to provide further insights into the nature of the electronic transitions for this class of complexes. One of the complexes has been found to show gelation properties, driven by π–π and hydrophobic–hydrophobic interactions. This complex exhibited concentration‐ and temperature‐dependent ¹H NMR spectra. The morphology of the gel has been characterized by transmission electron microscopy (TEM) and scanning electron microscopy (SEM).     

Syntheses,Characterization and X‐ray Structure of the First Silver(I) Complexes with 4‐Amino‐3‐thioxo‐3,4‐dihydro‐1,2,4‐triazin‐5(2H)‐one

Reaction of thiocarbohydrazide with glyoxolic acid monohydrate led to 4‐amino‐3‐thioxo‐3,4‐dihydro‐1,2,4‐triazin‐5(2H)‐one (AHTTO, 1 ). Treatment of 1 with AgNO₃ and PPh₃ gave thecomplexes [(PPh₃)₂Ag₂(μ‐N,S‐AHTTO)₂](NO₃)₂ ( 2 ) and [(PPh₃)₂Ag(AHTTO)]NO₃ · MeOH ( 3 ) was obtained under different conditions. All the compounds have been characterized by elemental analyses, IR spectroscopy and X‐ray diffraction studies.     

Metallkomplexe mit N2O2S2‐Koordinationssphäre. Synthese und Charakterisierung der Cobalt(II)‐, Nickel(II)‐ und Kupfer(II)‐Komplexe eines 15‐ und eines 16‐gliedrigen N,N′‐bis(2‐hydroxyethyl)‐funktionalisierten makrocyclischen Liganden

Metal Complexes with N₂O₂S₂ Donor Set. Synthesis and Characterization of the Cobalt(II), Nickel(II), and Copper(II) Complexes of a 15‐ and a 16‐Membered Bis(2‐hydroxyethyl) Pendant Macrocyclic Ligand The macrocyclic ligands 6, 10‐bis(2‐hydroxyethyl)‐7, 8, 9, 11, 17, 18‐hexahydro‐dibenzo‐[e, n][1, 4, 8, 12]‐dithiadiaza‐cyclopentadecine ( 1 ) (L¹) and 5, 13‐bis(2‐hydroxyethyl)‐7, 8, 9, 10, 16, 17, 18, 19, 20‐nonahydro‐dibenzo‐[g, o][1, 9, 5, 13]‐dithiadiaza‐cyclohexadecine (L⁴) have been prepared. They form the stable complexes [CoL¹(‐H)CoL¹](ClO₄)₃ ( 2 ), [NiL¹](ClO₄)₂·MeOH ( 3 ), Λ‐[CuL¹](ClO₄)₂·MeOH ( 4a ) and rac‐[CuL¹](ClO₄)₂·MeOH ( 4b ), [NiL⁴](ClO₄)₂ ( 5 ), and [CuL⁴](ClO₄)₂ ( 6 ). The compounds 1 to 6 have been characterized by standard methods and single‐crystal X‐ray diffraction. In the complexes 2 to 6 the metal atoms are octahedrally coordinated by the N₂O₂S₂ donor set of the ligands. L¹ and L⁴ are folded herein along the N···M···S‐ and the N···M···N′‐axes, respectively. This results at the metal atom in a all‐cis‐configuration for the complexes of L¹ and a trans‐N₂‐cis‐O₂‐cis‐S₂‐configuration for the complexes of L⁴. The cobalt(II) complex 2 is a dimer, bridged by a rather short hydrogen bridge of 2.402(12)Å length. The copper(II) complexes of L¹ and L⁴ differ with respect to the Jahn‐Teller‐distortion.     

Controlling Metal–Ligand–Metal Oxidation State Combinations by Ancillary Ligand (L) Variation in the Redox Systems [L2Ru(μ‐boptz)RuL2]n,boptz=3,6‐bis(2‐oxidophenyl)‐1,2,4,5‐tetrazine,and L=acetylacetonate, 2,2′‐bipyridine,or 2‐phenylazopyridine

The new compounds [(acac)₂Ru(μ‐boptz)Ru(acac)₂] ( 1 ), [(bpy)₂Ru(μ‐boptz)Ru(bpy)₂](ClO₄)₂ ( 2 ‐(ClO₄)₂), and [(pap)₂Ru(μ‐boptz)Ru(pap)₂](ClO₄)₂ ( 3 ‐(ClO₄)₂) were obtained from 3,6‐bis(2‐hydroxyphenyl)‐1,2,4,5‐tetrazine (H₂boptz), the crystal structure analysis of which is reported. Compound 1 contains two antiferromagnetically coupled (J=?36.7 cm^?1) Ru^III centers. We have investigated the role of both the donor and acceptor functions containing the boptz^2? bridging ligand in combination with the electronically different ancillary ligands (donating acac^?, moderately π‐accepting bpy, and strongly π‐accepting pap; acac=acetylacetonate, bpy=2,2′‐bipyridine pap=2‐phenylazopyridine) by using cyclic voltammetry, spectroelectrochemistry and electron paramagnetic resonance (EPR) spectroscopy for several in situ accessible redox states. We found that metal–ligand–metal oxidation state combinations remain invariant to ancillary ligand change in some instances; however, three isoelectronic paramagnetic cores Ru(μ‐boptz)Ru showed remarkable differences. The excellent tolerance of the bpy co ‐ ligand for both Ru^III and Ru^II is demonstrated by the adoption of the mixed ‐ valent form in [L₂Ru(μ‐boptz)RuL₂]³⁺, L=bpy, whereas the corresponding system with pap stabilizes the Ru^II states to yield a phenoxyl radical ligand and the compound with L=acac^? contains two Ru^III centers connected by a tetrazine radical‐anion bridge.     

Tris{2‐[N‐(diethylaminothiocarbonyl)benz(‐amidino;‐imidoxy;‐imidothio)‐N′‐yl]ethyl}amine – neue tripodale Liganden. Darstellung,Komplexstabilität und Extraktionsverhalten ihrer Silber(I)‐Komplexe

Tris{2‐[ N ‐(diethylaminothiocarbonyl)benz(‐amidino; imidoxy; ‐imidothio)‐ N ′‐yl]ethyl}amines – New Tripodal Ligands. Synthesis, Complex Stability, and Extraction Behaviour of their Silver(I) Complexes N‐(Thiocarbamoyl)‐benzimidoylchlorides react with trivalent nucleophiles to give four novel tripodal ligands. Two of them have been characterized by X‐ray methods. The ligands form with silver(I) cationic mononuclear complexes in which the three arms of the ligand are coordinated monodentately via sulfur. The results of FAB and ESI mass spectrometry as well as ESCA and NMR investigations verify this binding mode. The protonation constants of the ligands and the stability constants of silver(I) complexes have been determined potentiometrically. The novel tripodal compounds behave as powerful extractands for silver(I).     

Syntheses,Structures, and Photoluminescent and Magnetic Properties of Four Novel Complexes Constructed from 2,4,5‐Tri(4‐pyridyl)‐imidazole and Benzene‐1,3,5‐tricarboxylic Acid

Four novel 2D complexes M₂(Hptim)₂(HBTC)₂ [M = Co ( 1 ), Cd ( 2 ), Zn ( 3 ), Mn ( 4 ); Hptim = 2,4,5‐tri(4‐pyridyl)‐imidazole; HBTC^2– = Benzene‐1,3,5‐tricarboxylic acid] were synthesized under solvothermal conditions. The four complexes are isomorphous and present a unique structure with a 1D ladder of [Co₂(HBTC)₂]_n. The 2D network structure of 1 is achieved through bridging Hptim groups, which coordinate to the metal atoms of two adjacent 1D [Co₂(HBTC)₂]_n ladders. Magnetic measurements reveal that dominant antiferromagnetic coupling was observed in compounds 1 and 4 . Compounds 2 and 3 both exhibit strong fluorescent emissions in the solid state and may be suitable candidates for fluorescent materials.     

Chelation versus Binucleation: Metal Complex Formation with the Hexadentate all‐cis‐N1,N2‐Bis(2,4,6‐trihydroxy‐3,5‐diaminocyclohexyl)ethane‐1,2‐diamine

The hexadentate ligand all‐cis‐N¹,N²‐bis(2,4,6‐trihydroxy‐3,5‐diaminocyclohexyl)ethane‐1,2‐diamine (L^e) was synthesized in five steps with an overall yield of 39 % by using [Ni(taci)₂]SO₄?4 H₂O as starting material (taci=1,3,5‐triamino‐1,3,5‐trideoxy‐cis‐inositol). Crystal structures of [Na_0.5(H₆L^e)](BiCl₆)₂Cl_0.5?4 H₂O ( 1 ), [Ni(L^e)]‐ Cl₂?5 H₂O ( 2 ), [Cu(L^e)](ClO₄)₂?H₂O ( 3 ), [Zn(L^e)]CO₃?7 H₂O ( 4 ), [Co(L^e)](ClO₄)₃ ( 5 c ), and [Ga(H_?2L^e)]‐ NO₃?2 H₂O ( 6 ) are reported. The Na complex 1 exhibited a chain structure with the Na⁺ cations bonded to three hydroxy groups of one taci subunit of the fully protonated H₆(L^e)⁶⁺ ligand. In 2 , 3 , 4 , and 5 c , a mononuclear hexaamine coordination was found. In the Ga complex 6 , a mononuclear hexadentate coordination was also observed, but the metal binding occurred through four amino groups and two alkoxo groups of the doubly deprotonated H_?2(L^e)^2?. The steric strain within the molecular framework of various M(L^e) isomers was analyzed by means of molecular mechanics calculations. The formation of complexes of L^e with Mn^II, Cu^II, Zn^II, and Cd^II was investigated in aqueous solution by using potentiometric and spectrophotometric titration experiments. Extended equilibrium systems comprising a large number of species were observed, such as [M(L^e)]²⁺, protonated complexes [MH_z(L^e)]^2+z and oligonuclear aggregates. The pK_a values of H₆(L^e)⁶⁺ (25 °C, μ=0.10 m ) were found to be 2.99, 5.63, 6.72, 7.38, 8.37, and 9.07, and the determined formation constants (log β) of [M(L^e)]²⁺ were 6.13(3) (Mn^II), 20.11(2) (Cu^II), 13.60(2) (Zn^II), and 10.43(2) (Cd^II). The redox potentials (vs. NHE) of the [M(L^e)]^3+/2+ couples were elucidated for Co (?0.38 V) and Ni (+0.90 V) by cyclic voltammetry.     

An Easy One‐Pot Synthesis of Diverse 2,5‐Di(2‐pyridyl)pyrroles: A Versatile Entry Point to Metal Complexes of Functionalised,Meridial and Tridentate 2,5‐Di(2‐pyridyl)pyrrolato Ligands

A wide variety of 2,5‐di(2‐pyridyl)pyrroles (dppHs) substituted at the C3 and C4 positions of the pyrrole core were obtained by direct condensation of a 2‐pyridylcarboxaldehyde (2 equiv), an α‐methylene ketone with at least one electron‐withdrawing substituent and ammonium acetate. A novel 2,5‐di(1,10‐phenanthrolin‐2‐yl)pyrrole was also characterised. The dppHs provide a direct, quick entry to dipyridylpyrrolato (dpp^?)–metal complexes. The meridial tridentate dpp^? ligand is a useful anionic analogue of the terpyridyl ligand. The first (dpp)Ru complexes are described; the 3,4‐substitution of the central pyrrole significantly perturbs the potentials of the redox processes of these complexes. A [(dpp)Ru(bpy)(MeCN)]⁺ (bpy=2,2′‐bipyridine) complex is an electrocatalyst for the reductive disproportionation of carbon dioxide to carbon monoxide and the carbonate ion.     

Zinc(II) Tri‐tert‐butoxysilanethiolates. Synthesis,Properties, Crystal and Molecular Structures of [Zn{SSi(OBut)3}2(NH3)L] (L = 2‐Picoline or 2,4‐Lutidine) and [Zn{SSi(OBut)3}2(NH3)2] · MeCN Complexes

[Zn{SSi(OBu^t)₃}₂(NH₃)]₂ ( 1 ) reacts with 2‐picoline or 2,4‐lutidine (L) without elimination of ammonia giving stable monometallic complexes [Zn{SSi(OBu^t)₃}₂(NH₃)L] ( 3 and 4 ), with two different nitrogen ligands bonded to the metal center. Reaction of (Bu^tO)₃SiSH with zinc di(acetylacetonate) in ammonia atmosphere leads to the complex with two ammine ligands [Zn{SSi(OBu^t)₃}₂(NH₃)₂] · MeCN ( 5 ). Molecular and crystal structures of 3 , 4 and 5 have been determined by the single crystal X‐ray structural analysis. All have distorted tetrahedral geometry. The presence of ammonia gives rise to hydrogen bonds, different in all three cases. 3 , 4 , and 5 are the first examples of structurally characterized ammine ligated zinc thiolates.     

Regioselective ortho‐Metallation of 2‐Diphenylphosphanylpyridine and (2‐(2‐Diphenylphosphanyl)phenyl)‐1‐3‐dioxalane with Methyltetrakis(trimethylphosphane)cobalt(I)

Co(CH₃)(PMe₃)₄ forms 100 % regioselectively with (2‐(2‐diphenylphosphanyl)phenyl)‐1,3‐dioxalane and 2‐diphenylphosphanyl‐pyridine, by elimination of methane, the four‐membered metallacycles Co{(C₃O₂HC₆H₃)P(C₆H₅)₂}(PMe₃)₃ ( 1 ) and Co{(CNC₄H₃)P(C₆H₅)₂}(PMe₃)₃ ( 4 ). The regioselectivity is independent of the steric requirement of the ortho substituent in the 2‐diphenylphosphanylaryl‐ligands. Oxidative addition with iodomethane transforms 1 and 4 into octahedral, diamagnetic low‐spin d⁶ complexes Co(CH₃)I‐{(C₃O₂HC₆H₃)P(C₆H₅)₂}(PMe₃)₂ ( 2 ) and Co(CH₃)I‐{(CNC₄H₃)P(C₆H₅)₂}(PMe₃)₂ ( 5 ). Under an atmosphere of carbon monoxide, insertion into the Co‐C bond results in ring expansion by forming the new assembled phosphanylbenzoyl complexes Co{(C₄O₃HC₆H₃)‐P(C₆H₅)₂}CO(PMe₃)₂ ( 3 ) and Co{(OCNC₄H₃)P(C₆H₅)₂}CO(PMe₃)₂ ( 6 ). The three different types of cobaltacycles are supported by X‐ray diffraction of 1 , 3 , 5 and 6 .     

Synthesis,Characterization of a Novel 1,2,4‐Thiotriazine Derivative (CAMTTO), and Copper(I) and Silver(I) Complexes thereof (CAMTTO = {(4‐[(4‐Chlorobenzylidene)‐amino]‐6‐methyl‐3‐thioxo‐[1,2,4]‐triazin‐3,4‐dihydro(2H)‐5‐one)}

The reaction of 4‐amino‐6‐methyl‐1,2,4‐triazin‐thione‐5‐one (H₂AMTTO, 1 ) with 4‐chlorobenzaldhyde led to the corresponding iminic compound {(4‐[(4‐chloro‐benzylidene)‐amino]‐6‐methyl‐3‐thioxo[1,2,4]‐triazin‐3,4‐dihydro(2H)‐5‐one), CAMTTO ( 2 ). Treatment of 2 with copper(I) chloride in chloroform gave the dimeric complex [{(CAMTTO)₂CuCl}₂]·2CHCl₃ ( 3 ). Treatment of 2 with copper(I) chloride and silver(I) nitrate in the presence of the co‐ligand triphenylphophane gave the complexes [(CAMTTO)CuCl(PPh₃)₂] ( 4 ) and [(CAMTTO)Ag(PPh₃)₂]NO₃·2CHCl₃ ( 5 ). All compounds have been characterized by elemental analyses, ¹H NMR spectroscopy, IR spectroscopy, and partly by mass spectrometry and X‐ray diffraction studies. In addition 4 and 5 have been characterized by ³¹P{¹H} NMR spectroscopy. Crystal data for 2 at ?80 °C: monoclinic, space group P2₁/c, a = 1370.3(1), b = 767.8(1), c = 1268.7(1) pm, β = 107.12(1)°, Z = 4, R₁ = 0.0379; for 3 at ?80 °C: monoclinic, space group P2₁/c, a = 1442.6(2), b = 878.8(1), c = 2558.7(3) pm, β = 95.31(1)°, Z = 2, R₁ = 0.0746; for 4 at ?80 °C: triclinic, space group , a = 1287.9(1), b = 1291.7(1), c = 1359.5(1) pm, α = 90.44(1)°, β = 94.81(1)°, γ = 107.54(1)°, Z = 2, R₁ = 0.0359 and for 5 at ?80 °C: triclinic, space group , a = 1060.5(1), b = 1578.2(2), c = 1689.6(2) pm, α = 87.70(1)°, β = 86.66(1)°, γ = 76.84(1)°, Z = 2, R₁ = 0.0487.     

Metalated 1, 3‐Azaphospholes: η1‐(1H‐1, 3‐Benzazaphosphole‐P)M(CO)5 and μ2‐[(1, 3‐Benzazaphospholide‐P)(cyclopentadienide)nickel] Complexes

1H‐1, 3‐Benzazaphospholes react with M(CO)₅(THF) (M = Cr, Mo, W) to give thermally and relatively air stable η¹‐(1H‐1, 3‐Benzazaphosphole‐P)M(CO)₅ complexes. The ¹H‐ and ¹³C‐NMR‐data are in accordance with the preservation of the phosphaaromatic π‐system of the ligand. The strong upfield ³¹P coordination shift, particularly of the Mo and W complexes, forms a contrast to the downfield‐shifts of phosphine‐M(CO)₅ complexes and classifies benzazaphospholes as weak donor but efficient acceptor ligands. Nickelocene reacts as organometallic species with metalation of the NH‐function. The resulting ambident 1, 3‐benzazaphospholide anions prefer a μ₂‐coordination of the η⁵‐CpNi‐fragment at phosphorus to coordination at nitrogen or a η³‐heteroallyl‐η⁵‐CpNi‐semisandwich structure. This is shown by characteristic NMR data and the crystal structure analysis of a η⁵‐CpNi‐benzazaphospholide. The latter is a P‐bridging dimer with a planar Ni₂P₂ ring and trans‐configuration of the two planar heterocyclic phosphido ligands arranged perpendicular to the four‐membered ring.     

N,N, N′, N′‐Tetrakis(diphenylphosphanyl)‐1, 3‐diaminobenzene as a Bis‐chelate Ligand in [1, 3‐{cis‐Mo(CO)4(PPh2)2N}2C6H4]

1, 3‐Diaminobenzene reacts readily with PPh₂Cl to give N, N, N′, N′‐tetrakis(diphenylphosphanyl)‐1, 3‐diaminobenzene ( 1 ) in excellent yield. The dinuclear complex [1, 3‐{cis‐Mo(CO)₄(PPh₂)₂N}₂C₆H₄] ( 2 ) is obtained in high yield from 1 and cis‐[Mo(CO)₄(NCEt)₂]. Compounds 1 and 2 were characterized by NMR spectroscopy (¹H, ¹³C, ³¹P) and by crystal structure determination. The latter shows the formation of a bis‐chelate complex with Mo‐P‐N‐P four‐membered rings.     

Copper(II) and Sodium(I) Complexes based on 3,7‐Diacetyl‐1,3,7‐triaza‐5‐phosphabicyclo[3.3.1]nonane‐5‐oxide: Synthesis,Characterization, and Catalytic Activity

The reaction of 3,7‐diacetyl‐1,3,7‐triaza‐5‐phosphabicyclo[3.3.1]nonane (DAPTA) with metal salts of Cu^II or Na^I/Ni^II under mild conditions led to the oxidized phosphane derivative 3,7‐diacetyl‐1,3,7‐triaza‐5‐phosphabicyclo[3.3.1]nonane‐5‐oxide (DAPTA=O) and to the first examples of metal complexes based on the DAPTA=O ligand, that is, [Cu^II(μ‐CH₃COO)₂(κO‐DAPTA=O)]₂ ( 1 ) and [Na(1κOO′;2κO‐DAPTA=O)(MeOH)]₂(BPh₄)₂ ( 2 ). The catalytic activity of 1 was tested in the Henry reaction and for the aerobic 2,2,6,6‐tetramethylpiperidin‐1‐oxyl (TEMPO)‐mediated oxidation of benzyl alcohol. Compound 1 was also evaluated as a model system for the catechol oxidase enzyme by using 3,5‐di‐tert‐butylcatechol as the substrate. The kinetic data fitted the Michaelis–Menten equation and enabled the obtainment of a rate constant for the catalytic reaction; this rate constant is among the highest obtained for this substrate with the use of dinuclear Cu^II complexes. DFT calculations discarded a bridging mode binding type of the substrate and suggested a mixed‐valence Cu^II/Cu^I complex intermediate, in which the spin electron density is mostly concentrated at one of the Cu atoms and at the organic ligand.     

Synthesis,Crystal Structure,and Characterization of Two Novel Five‐coordinate Zinc(II) Complexes with the Tripod Ligand Tris(N‐methylbenzimidazol‐2‐yl‐methyl)amine and α,β‐unsaturated Carboxylates

Two novel five‐coordinate zinc(II) complexes with the tripod ligand tris(N‐methylbenzimidazol‐2‐ylmethyl)amine (Mentb) and two different α,β‐unsaturated carboxylates, with the composition [Zn(Mentb)(acrylate)] (ClO₄)·DMF·1.5CH₃OH ( 1 ) and [Zn(Mentb)(cinnamate)](ClO₄)·2DMF·0.5CH₃OH ( 2 ), were synthesized and characterized by means of elemental analyses, electrical conductivity measurements, IR, UV, and ¹H NMR spectra. The crystal structure of two complexes have been determined by a single‐crystal X‐ray diffraction method, and show that the Zn^II atom is bonded to a Mentb ligand and a α,β‐unsaturated carboxylate molecule through four N atoms and one O atom, resulting in a distorted trigonal‐bipyramidal coordination [τ( 1 ) = 0.853, τ( 2 ) = 0.855], with approximate C₃ symmetry.     

Total Synthesis of (R,R,R)‐α‐Tocopherol Through Asymmetric Cu‐Catalyzed 1,4‐Addition

By introducing a disposable activating substituent at C‐3, the asymmetric 1,4‐addition to a notoriously unreactive 2‐substituted chromenone was achieved with high levels of (2R)‐stereoselectivity in the presence of a chiral Cu^I‐phosphoramidite complex as a catalyst. This paved the way for an efficient and conceptually novel synthesis of (R,R,R)‐α‐tocopherol from readily available starting materials.     

N,N′‐Bis(Salicylidene)‐1,2‐Cyclohexanediamine Lanthanide(III) Coordination Polymers: Syntheses,Crystal Structures,and Luminescence Properties

The salen‐type ligand H₂L [H₂L = N,N′‐bis(salicylidene)‐1,2‐cyclohexanediamine] was utilized for the synthesis of two lanthanide(III) coordination polymers [LnH₂L(NO₃)₃MeOH]_n [Ln = Eu ( 1 ) and Ln = Lu ( 2 )]. The single‐crystal X‐ray diffraction analyses of 1 and 2 revealed that they are isomorphous and exhibit one‐dimension neutral structure, in which H₂L effectively functions as a bridging ligand and give rise to a chain‐like polymer. The luminescent properties of polymers in solid state and in solution were investigated and 1 exhibits typical red luminescence of Eu^III ions in solid state and dichloromethane solution and 2 emits the ligand‐centered blue luminescence. The energy transfer mechanisms in these luminescent lanthanide polymers were described through calculation of the lowest triplet level of ligand H₂L.     

Synthesis,Crystal Structure and Spectroscopic Properties of [2,13‐Bis(1‐naphthalenylmethyl)‐5,16‐dimethyl‐2,6,13,17‐tetraazatricyclo(14,4,01.18,07.12)docosane]copper(II) Diperchlorate Acetonitrile Disolvate

The N‐functionalized macrocyclic ligand 2,13‐bis(1‐naphthalenylmethyl)‐5,16‐dimethyl‐2,6,13,17‐tetraazatricyclo(14,4,0^1.18,0^7.12)docosane (L³) and its copper(II) complex were prepared. The crystal structure of [Cu(L³)](ClO₄)₂·2CH₃CN was determined by single‐crystal X‐ray diffraction at 150 K. The copper atom, which lies on an inversion centre, has a square planar arrangement and the complex adopts a stable trans‐III configuration. The longer distance [2.081(2) Å] for Cu–N(tertiary) compared to 2.030(3) Å for Cu–N(secondary) may be due to the steric effect of the attached naphthalenylmethyl group on the tertiary nitrogen atom. Two perchlorate ions are weakly attached to copper in axial sites and are further connected to the ligand of the cation through NH ··· O hydrogen bonds [N ··· O 3.098 Å]. IR and UV/Vis spectroscopic properties are also described.     

Halogenido and Pseudohalogenido Complexes of (2,3,7,8,12,13,17,18‐Octaethyl‐5,15‐di‐p‐tolylcorrolato)manganese(IV)

A set of porphyrinoid manganese(IV) complexes with the 2,3,7,8,12,13,17,18‐octaethyl‐5,15‐di‐p‐tolylcorrolato ligand [(oedtc)Mn^IVX] (X = Cl, Br, I) was prepared by oxidation of a manganese(III) precursor. The most unexpected complex in this series, [(oedtc)Mn^IVI], was found to display significant thermal stability despite the unusual Mn^IV‐I bond and could be investigated by X‐ray diffraction. Attempted ligand exchange reactions of the chlorido derivative with the pseudohalide anions cyanide, azide, cyanate and thiocyanate yielded the desired [(oedtc)Mn^IVX] complex only as the isothiocyanate derivative while for the other species the reduction to manganese(III) was observed.