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There is considerable interest in MnOH x moieties, particularly in the stepwise changes in those O-H bonds in tandem with Mn oxidation state changes. The reactivity of aquo-derived ligands, {MOH x }, is also heavily influenced by the electronic character of the other ligands. Despite the prevalence of oxygen coordination in biological systems, preparation of mononuclear Mn complexes of this type with all O-donors is rare. Herein, we report several Mn complexes with perfluoropinacolate (pin F ) 2- including the first example of a crystallographically characterized mononuclear {Mn(iii)OH} with all O-donors, K 2 [Mn(OH)(pin F ) 2 ], 3. Complex 3 is prepared via deprotonation of K[Mn(OH 2 )(pin F ) 2 ], 1, the p K a of which is estimated to be 18.3 ± 0.3. Cyclic voltammetry reveals quasi-reversible redox behavior for both 1 and 3 with an unusually large Δ E p , assigned to the Mn(iii/ii) couple. Using the Bordwell method, the bond dissociation free energy (BDFE) of the O-H bond in {Mn(ii)-OH 2 } is estimated to be 67-70 kcal mol -1 . Complex 3 abstracts H-atoms from 1,2-diphenylhydrazine, 2,4,6-TTBP, and TEMPOH, the latter of which supports a PCET mechanism. Under basic conditions in air, the synthesis of 1 results in K 2 [Mn(OAc)(pin F ) 2 ], 2, proposed to result from the oxidation of Et 2 O to EtOAc by a reactive Mn species, followed by ester hydrolysis. Complex 3 alone does not react with Et 2 O, but addition of O 2 at low temperature effects the formation of a new chromophore proposed to be a Mn(iv) species. The related complexes K(18C6)[Mn(iii)(pin F ) 2 ], 4, and (Me 4 N) 2 [Mn(ii)(pin F ) 2 ], 5, have also been prepared and their properties discussed in relation to complexes 1-3., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

High quality epitaxial thin films of the quasi-one dimensional conductor K 0.3 MoO 3 have been successfully grown on SrTiO 3 (100), SrTiO 3 (110), and SrTiO 3 (510) substrates via pulsed laser deposition. Scanning electron microscopy revealed quasi-one dimensional rod-shaped structures parallel to the substrate surface, and the crystal structure was verified by using X-ray diffraction. The temperature dependence of the resistivity for the K 0.3 MoO 3 thin films demonstrates a metal-to-semiconductor transition at about 180 K. Highly anisotropic resistivity was also observed for films grown on SrTiO 3 (510)., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

The synthesis and characterization of a series of Sn(ii) and Sn(iv) complexes supported by the highly electron-withdrawing dianionic perfluoropinacolate (pin F ) ligand are reported herein. Three analogs of [Sn IV (pin F ) 3 ] 2- with NEt 3 H + (1), K + (2), and {K(18C6)} + (3) counter cations and two analogs of [Sn II (pin F ) 2 ] 2- with K + (4) and {K(15C5) 2 } + (5) counter cations were prepared and characterized by standard analytical methods, single-crystal X-ray diffraction, and 119 Sn Mössbauer and NMR spectroscopies. The six-coordinate Sn IV (pin F ) complexes display 119 Sn NMR resonances and 119 Sn Mössbauer spectra similar to SnO 2 (cassiterite). In contrast, the four-coordinate Sn II (pin F ) complexes, featuring a stereochemically-active lone pair, possess low 119 Sn NMR chemical shifts and relatively high quadrupolar splitting. Furthermore, the Sn(ii) complexes are unreactive towards both Lewis bases (pyridine, NEt 3 ) and acids (BX 3 , Et 3 NH + ). Calculations confirm that the Sn(ii) lone pair is localized within the 5s orbital and reveal that the Sn 5p x LUMO is energetically inaccessible, which effectively abates reactivity.

The new PtVO(SOCR)4 lantern complexes, 1 (R = CH3) and 2 (R = Ph) behave as neutral O-donor ligands to Ln(OR)3 with Ln = Ce, Nd. Four heterotrimetallic complexes with linear {LnOVPt} units were prepared: [Ln(ODtbp)3{PtVO(SOCR)4}] (Ln = Ce, 3Ce (R = CH3), 4Ce (R = Ph); Nd, 3Nd (R = CH3), 4Nd (R = Ph); ODtbp = 2,6-ditertbutylphenolate). Magnetic characterization confirms slow magnetic relaxation behaviour and suggests antiferromagnetic coupling across {Ln-O[double bond, length as m-dash]V} in all four complexes, with variations tunable as a function of Ln and R.

A Cu(i) fully fluorinated O-donor monodentate alkoxide complex, K[Cu(OC4F9)2], was previously shown to form a trinuclear copper-dioxygen species with a {Cu3(μ3-O)2} core, TOC4F9, upon reactivity with O2 at low temperature. Herein is reported a significantly expanded kinetic and mechanistic study of TOC4F9 formation using stopped-flow spectroscopy. The TOC4F9 complex performs catalytic oxidase conversion of hydroquinone (H2Q) to benzoquinone (Q). TOC4F9 also demonstrated hydroxylation of 2,4-di-tert-butylphenolate (DBP) to catecholate, making TOC4F9 the first trinuclear species to perform tyrosinase (both monooxygenase and oxidase) chemistry. Resonance Raman spectra were also obtained for TOC4F9, to our knowledge, the first such spectra for any T species. The mechanism and substrate reactivity of TOC4F9 are compared to those of its bidentate counterpart, TpinF, formed from K[Cu(pinF)(PR3)]. The monodentate derivative has both faster initial formation and more diverse substrate reactivity.

Investigation of Cu-O2 oxidation reactivity is important in biological and anthropogenic chemistry. Zeolites are one of the most promising Cu/O based oxidation catalysts for development of industrial-scale CH4 to CH3OH conversion. Their oxidation mechanisms are not well understood, however, highlighting the importance of the investigation of molecular Cu(i)-O2 reactivity with O-donor complexes. Herein, we give an overview of the synthesis, structural properties, and O2 reactivity of three different series of O-donor fluorinated Cu(i) alkoxides: K[Cu(OR)2], [(Ph3P)Cu(μ-OR)2Cu(PPh3)], and K[(R3P)Cu(pinF)], in which OR = fluorinated monodentate alkoxide ligands and pinF = perfluoropinacolate. This breadth allowed for the exploration of the influence of the denticity of the ligand, coordination number, the presence of phosphine, and KF/O interactions on their O2 reactivity. KF/O interactions were required to activate O2 in the monodentate-ligand-only family, whereas these connections did not affect O2 activation in the bidentate complexes, potentially due to the presence of phosphine. Both families formed trisanionic, trinuclear cores of the form {Cu3(μ3-O)2}3-. Intramolecular and intermolecular substrate oxidation were also explored and found to be influenced by the fluorinated ligand. Namely, {Cu3(μ3-O)2}3- from K[Cu(OR)2] could perform both monooxygenase reactivity and oxidase catalysis, whereas those from K[(R3P)Cu(pinF)] could only perform oxidase catalysis.

Oxidation of distorted square-planar perfluoropinacolate Co compound [CoII(pinF)2]2-, 1, to [CoIII(pinF)2]1-, 2, is reported. Rigidly square-planar 2 has an intermediate-spin, S = 1, ground state and very large zero-field splitting (ZFS) with D = 67.2 cm-1; |E| = 18.0 cm-1, (E/D = 0.27), g⊥ = 2.10, g‖ = 2.25 and χTIP = 1950 × 10-6 cm3 mol-1. This Co(iii) species, 2, reacts with ROS to oxidise two (pinF)2- ligands to form tetrahedral [CoII(Hpfa)4]2-, 3.

Four new quasi-1D Ni 2 -lantern chain complexes of the form [Ni 2 (SOCR) 4 (L)] ∞ (R = Ph, L = DABCO (1); R = Ph, L = pyz (2); R = CH 3 , L = DABCO (3); R = CH 3 , L = pyz (4)) were prepared from the reaction of [Ni 2 (SOCR) 4 (EtOH)], R = CH 3 or Ph, with the N,N'-donor bridging ligands pyrazine (pyz) or 1,4-diazabicyclo[2.2.2]octane (DABCO). Reaction of [Ni 2 (tba) 4 (EtOH)], (tba = thiobenzoate) with the mono-N donor ligand quinuclidine (quin) gave the discrete Ni 2 -lantern complex [Ni 2 (tba) 4 (quin)] (5), whereas reaction with pyridine led to fragmentation of the lantern and formation of the known [Ni(tba) 2 (py) 2 ] (6). Single-crystal X-ray diffraction reveals 2-4 to be 1D chain complexes comprising DABCO or pyz ligands which bridge the Ni 2 -lantern units. Complex 5 forms dimers through two equivalent NiS interactions. The Ni-Ni distances within the Ni 2 -lanterns are 2.5316(18)-2.595(2) Å for the 1D chain complexes 2-4, and 2.5746(4) Å in the dimeric complex 5, respectively. Comparing the solid state magnetism of 5 to precursor [Ni 2 (tba) 4 (EtOH)] demonstrates a change in coupling upon change of capping ligand. Meanwhile, chains 1-4 exhibit magnetic properties consistent with an S = 1 system, due to a mixed valent system where the two Ni centers differ in spin state, while 5 possesses two S = 1 Ni(ii) centers. DFT calculations confirm low-spin S = 0 {NiS 4 } and high-spin S = 1 {NiO 4 } centers in each lantern. Fits to the magnetic susceptibility data of the chains suggest a weak antiferromagnetic mean field interaction is present that is largely 1-D in nature, though neither pyrazine nor DABCO promote significant magnetic interaction between neighboring Ni 2 -lanterns.

Exploitation of HSAB preferences allows for high-yield, one-pot syntheses of lanthanide complexes chelated by two Pd or Pt metalloligands, [M II (SAc) 4 ] 2- (SAc - = thioacetate, M = Pd, Pt). The resulting complexes with 8 oxygen donors surrounding the lanthanides can be isolated in crystallographically tetragonal environments as either [NEt 4 ] + (space group: P 4/ mcc ) or [PPh 4 ] + (space group: P 4/ n ) salts. In the case of M = Pt, the complete series of lanthanide complexes has been structurally characterized as the [NEt 4 ] + salts (except for Ln = Pm), while the [PPh 4 ] + salts have been structurally characterized for Ln = Gd-Er, Y. For M = Pd, selected lanthanide complexes have been structurally characterized as both salts. The only significant structural difference between salts of the two counter ions is the resulting twist angle connecting tetragonal prismatic and tetragonal anti-prismatic configurations, with the [PPh 4 ] + salts approaching ideal D 4d symmetry very closely ( φ = 44.52-44.61°) while the [NEt 4 ] + salts exhibit intermediate twist angles in the interval φ = 17.28-27.41°, the twist increasing as the complete 4f series is traversed. Static magnetic properties for the latter half of the lanthanide series are found to agree well in the high temperature limit with the expected Curie behavior. Perpendicular and parallel mode EPR spectroscopy on randomly oriented powder samples and single crystals of the Gd complexes with respectively Pd- and Pt-based metalloligands demonstrate the nature of the platinum metal to strongly affect the spectra. Consistent parametrization of all of the EPR spectra reveals the main difference to stem from a large difference in the magnitude of the leading axial term, B 02, this being almost four times larger for the Pt-based complexes as compared to the Pd analogues, indicating a direct Pt(5d z 2 )-Ln interaction and an arguable coordination number of 10 rather than 8. The parametrization of the EPR spectra also confirms that off-diagonal operators are associated with non-zero parameters for the [NEt 4 ] + salts, while only contributing minimally for the [PPh 4 ] + salts in which lanthanide coordination approximates D 4d point group symmetry closely.

Herein we report the first structural characterization of a Pt(iv)-kappa(3)-terpyridine species, [Pt((t)Bu(3)tpy)Cl(3)][AuCl(2)], which can be prepared by oxidation with [AuCl(4)](-). The syntheses and characterization of [Pt((t)Bu(3)tpy)Cl(3)]Cl ((t)Bu(3)tpy is 4,4',4''-tri-tert-butyl-2,2':6',2''-terpyridine), as well as the platinum(ii) complexes [Pt((t)Bu(3)tpy)Cl]Cl and [Pt((t)Bu(3)tpy)Cl][AuCl(2)] are reported.

This Perspective highlights our efforts to assemble infinite chains of metal atoms in double salts of the form [M](+)[M](-) under the complementary influences of metallophilic interactions and electrostatic attraction. Our design strategy necessarily incorporates the significant steric constraints of one-dimensional assemblies as well as the more subtle and challenging electronic tuning of weak dispersion forces.

The element and orbital-specific electronic structure of thin films of the organic material N,N'-ethylene-bis(1,1,1-trifluoropentane-2,4-dioneiminato)-copper(II) (designated as Cu-TFAC) has been studied using a combination of synchrotron radiation-excited resonant X-ray emission spectroscopy, X-ray photoelectron spectroscopy, X-ray absorption spectroscopy and density functional theory calculations. Furthermore, resonant X-ray emission at the carbon K-edge was used to measure the density of states for individual C sites in the molecule.

Homoleptic fluorinated alkoxide complexes have been prepared from KOC4F9, 1, via salt metathesis routes. One four-coordinate K{K(18C6)}[Co(OC4F9)4], 2, and four three-coordinate complexes: {K(18C6)}[Fe(OC4F9)3], 3, {K(18C6)}[Co(OC4F9)3], 4, {K(18C6)}[Cu(OC4F9)3], 5, and {K(18C6)}[Zn(OC4F9)3], 6, have been prepared and all except 5 have been characterized crystallographically. Compounds 3, 4, and 6 are very rare examples of monomeric, trigonal alkoxide complexes. All compounds have been characterized with UV-vis and IR spectroscopy, solution magnetic susceptibility, and elemental analysis. In solution, compound 2 exists in an equilibrium with 4 and 1, which has been probed with cyclic voltammetry, supporting energetically different Co2+/Co3+ potentials in the three-coordinate (E(p,a) = approximately 1.2 V vs Fc/Fc+) and four-coordinate (E(p,a) = approximately 0.9 V) geometries. The ligand field engendered by the perfluoro-t-butoxide ligand has been studied with DFT calculations on 4 and the hypothetical [Co(OC4H9)3]- as well as the previously reported [Co(mes)3]- and [Co{N(TMS)2}3]- showing significant -type interactions in the xy plane as well as above and below for the two alkoxide species.

A series of [Cu(L(3)')(NCS)(L/X)](+/0) complexes (L(3)' = 4,4',4''-tri-tert-butyl-2,2':6',2''-terpyridine; L = CH(3)OH; X = NCS, [NCAuCN]) has been prepared and characterized with X-ray crystallography, UV-vis and IR spectroscopies, and DFT calculations. The structure of starting material [Cu(L(3)')(NO(3))(2)], , was determined as well as the structures of the five-coordinate copper isothiocyanate complexes [Cu(L(3)')(NCS)(MeOH)](PF(6)), , [Cu(L(3)')(NCAuCN)(NCS)], , and two pseudo-polymorphs of bis-isothiocyanate [Cu(L(3)')(NCS)(2)], 3a and 3b.CH(3)CN. The square pyramidal structures of and differ markedly from the more trigonal bipyramidal [Cu(terpy)(NCS)(2)]. Electronic structure calculations suggest that the sigma-donor ability of the polyimine ligand controls the metal center geometry. The IR spectroscopic analysis shows that the nu(CN) stretching frequencies do not correlate predictably with structural parameters, such as the Cu-N-CS bond angle, demonstrating the oversimplification of the linear Cu-N[triple bond, length as m-dash]C-S vs. bent Cu-N=C=S modelling of isothiocyanate bonding.