Crystal structure and synthesis of the bis(anthracene)dicuprate dianion as the dipotassium salt, [K(tetrahydrofuran)][{Cu(9,10-η-anthracene)}], the first anionic arene complex of copper.

Reactions of (tricyclohexylphosphane)copper(I) chloride with two equivalents of potassium anthracene (KAn) in tetrahydrofuran (THF) at 200 K provides air-sensitive but thermally stable (at 293 K) solutions from which yellow crystalline blocks of bis[bis(tetrahydrofuran-κO)potassium] bis(μ-anthracene-κC:C)dicopper, [K(THF)][{Cu(9,10-η-CH)}] or [K(CHO)][Cu(CH)], 1, were isolated in about 50% yield. Single-crystal X-ray crystallographic analysis of 1 confirmed the presence of the first known (arene)cuprate. Also, unlike all previously known homoleptic (anthracene)metallates of d-block elements, which contain metals coordinated only to terminal rings, the organocuprate unit in 1 contains copper bound to the 9,10-carbons of the central ring of anthracene.

Syntheses and crystal structures of new naphthalene- and anthracene-vanadate salts and an unprecedented dimetallabis(anthracene) sandwich complex: [Na(tetrahydrofuran)][V(anthracene)].

Reduction of bis(naphthalene)vanadium(0) by potassium naphthalene (KNp) in tetrahydrofuran (THF) provides a highly reactive, thermolabile, and so far unisolable brown substance, which affords the first reported derivatives of bis(naphthalene)vanadates. From these solutions, thermally stable (298 K) and structurally characterized compounds have been obtained, including dark-red rods of catena-poly[bis(μ-η:η:η-naphthalene)tetrakis(tetrahydrofuran)dipotassiumvanadium], [KV(CHO)(CH)] or [K(THF)][V(CH)] (3), and red plates of (4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.

Crystal structures of two novel iron isocyanides from the reaction of 2,6-di-methyl-phenyl isocyanide, CNXyl, with bis-(anthracene)ferrate(-1).

The reaction of the [K(18-crown-6)(thf)] (thf is tetra-hydro-furan) salt of bis-(anthracene)ferrate(-1), or [Fe(CH)], with 2,6-di-methyl-phenyl isocyan-ide (CNX-yl) in thf resulted in the formation of two new iron isocyanide complexes, namely, [(1,2,3,4-η)-anthracene]tris-(2,6-di-methyl-phenyl isocyanide)iron, [Fe(CH)(CHN)] or [Fe(1,2,3,4-η-CH)(CNX-yl)], and {5,6-bis-(2,6-di-methyl-anilino)-3-(2,6-di-methyl-phen-yl)-1,2,7-tris-[(2,6-di-methyl-phen-yl)imino]-3-azoniahept-3-ene-1,4,7-triido}tris-(2,6-di-methyl-phenyl isocyanide)iron tetra-hydro-furan disolvate, [Fe(CHN)(CHN)]·2CHO or [Fe(CHN)(CNX-yl)]·2CHO, which were characterized by single-crystal X-ray diffraction. The former is likely an inter-mediate along the path to the known homoleptic [Fe(CNX-yl)], while the latter contains a tridentate ligand that is formed from the 'coupling' of six CNXyl ligands. A third crystal structure from this reaction, (7-methyl-indol-1-ido-κ)(1,4,7,10,13,16-hexa-oxa-cyclo-octa-decane-κ )potassium, [K(CHN)(CHO)] or [K(CHN)(18-crown-6)], contains a 7-methyl-indol-1-ide anion, in which one CNXyl ligand has shed a proton during its reductive cyclization.

Effect of Spin-Orbit Coupling on Phonon-Mediated Magnetic Relaxation in a Series of Zero-Valent Vanadium, Niobium, and Tantalum Isocyanide Complexes.

Spin-vibronic coupling leads to spin relaxation in paramagnetic molecules, and an understanding of factors that contribute to this phenomenon is essential for designing next-generation spintronics technology, including single-molecule magnets and spin-based qubits, wherein long-lifetime magnetic ground states are desired. We report spectroscopic and magnetic characterization of the isoelectronic and isostructural series of homoleptic zerovalent transition metal triad M(CNDipp) (M = V, Nb, Ta; CNDipp = 2,6-diisopropylphenyl isocyanide) and show experimentally the significant increase in spin relaxation rate upon going from V to Nb to Ta. Correlated electronic calculations and first principle spin-phonon computations support the role of spin-orbit coupling in modulating spin-phonon relaxation.

Correction: The Chatt reaction: conventional routes to homoleptic arenemetalates of d-block elements.

Correction for 'The Chatt reaction: conventional routes to homoleptic arenemetalates of d-block elements' by John E. Ellis et al., Dalton Trans.

Niobium isocyanide complexes, Nb(CNAr), with Ar = 2,6-dimethylphenyl (Xyl), a diamagnetic dimer containing four reductively coupled isocyanides, and Ar = 2,6-diisopropylphenyl (Dipp), a paramagnetic monomer analogous to the highly unstable hexacarbonylniobium(0).

Treatment of bis(mesitylene)niobium(0) with 6-7 equivalents of 2,6-dimethylphenyl isocyanide (CNXyl) affords two products with the empirical formula Nb(CNXyl) (n = 7 or 6), which have been shown to be the diamagnetic dimers bis[μ-N,N',N'',N'''-tetrakis(2,6-dimethylphenyl)squaramidinato(2-)]bis[pentakis(2,6-dimethylphenyl isocyanide)niobium(I)], [Nb(CHN)(CHN)] or [Nb(CNXyl)][μ-C(NXyl)]·xSolvent, 1, and bis[μ-N,N',N'',N'''-tetrakis(2,6-dimethylphenyl)squaramidinato(2-)]bis[tetrakis(2,6-dimethylphenyl isocyanide)niobium(I)] tetrahydrofuran trisolvate, [Nb(CHN)(CHN)]·3CHO or [Nb(CNXyl)][μ-C(NXyl)]·3THF (THF = tetrahydrofuran), 2. Each contains Nb bound to either five or four terminal isocyanides, respectively, and to an unprecedented bridging tetraarylsquaramidinate(2-) unit, coordinated as a bidentate ligand to each niobium center, symmetrically due to the crystallographic inversion center that coincides with the centroid of the central C unit. Thus, in the presence of CNXyl, the bis(mesitylene)niobium(0) is oxidized to niobium(I), resulting in the facile loss of both mesitylene groups and the reductive coupling of two CNXyl groups per niobium to provide the first examples of tetraarylsquaramidinate(2-) ligands, [cyclo-CNAr], coordinated to metals.

Crystal structures and spectroscopic characterization of MBr(CNXyl) (M = Fe and Co, n = 4; M = Ni, n = 2; Xyl = 2,6-dimethylphenyl), and of formally zero-valent iron as a cocrystal of Fe(CNXyl) and Fe(CNXyl).

Structures and spectroscopic characterization of the divalent complexes cis-dibromidotetrakis(2,6-dimethylphenyl isocyanide)iron(II) dichloromethane 0.771-solvate, [FeBr(CHN)]·0.771CHCl or cis-FeBr(CNXyl)·0.

The Chatt reaction: conventional routes to homoleptic arenemetalates of d-block elements.

Joseph Chatt was the first to discover in the early 1960s that previously unknown transition metal compounds were accessible and isolable via the reactions of alkali metal arene radical anions with transition metal precursors containing good leaving groups, such as weakly basic neutral or anionic ligands, especially halides. Later Peter Timms confirmed the importance of these early studies with the synthesis of several new bis(arene)metal(0) sandwich compounds by a variant of Chatt's route. Following a brief historical survey of alkali metal arene compounds, first examined in some detail by Wilhelm Schlenk, use of these reagents in the conventional syntheses of anionic homoleptic arene metal complexes of the d-block elements will be described.

Tantalum isocyanide complexes: TaI(CNDipp) (Dipp is 2,6-diisopropylphenyl) and ionic [Ta(CNDipp)][Ta(CNDipp)], a formal disproportionation product of the 17-electron Ta metalloradical Ta(CNDipp).

Treatment of tetraethylammonium hexacarbonyltantalate, [EtN][Ta(CO)], with 1.1 equivalents of molecular iodine (I) in tetrahydrofuran (THF) at 200 K, followed by the addition of 6.0 equivalents of 2,6-diisopropylphenyl isocyanide (CNDipp) and slow warming to 293 K over a 24 h period gave the tantalum(I) iodide derivative hexakis(2,6-diisopropylphenyl isocyanide-κC)iodidotantalum(I), [TaI(CHN)] or TaI(CNDipp), 1.

Scandium complexes with the tetraphenylethylene and anthracene dianions.

The structural study of Sc complexes containing dianions of anthracene and tetraphenylethylene should shed some light on the nature of rare-earth metal-carbon bonding. The crystal structures of (18-crown-6)bis(tetrahydrofuran-κO)sodium bis(η-1,1,2,2-tetraphenylethenediyl)scandium(III) tetrahydrofuran disolvate, [Na(CHO)(CHO)][Sc(CH)]·2CHO or [Na(18-crown-6)(THF)][Sc(η-CPh)]·2(THF), (1b), (η-1,3-diphenylcyclopentadienyl)(tetrahydrofuran-κO)(η-1,1,2,2-tetraphenylethenediyl)scandium(III) toluene hemisolvate, [Sc(CH)(CH)(CHO)]·0.5CH or [(η-1,3-PhCH)Sc(η-CPh)(THF)]·0.

Ta(CNDipp) : An Isocyanide Analogue of Hexacarbonyltantalum(0).

Hexakis(2,6-diisopropylphenylisocyanide)tantalum is the first isocyanide analogue of the highly unstable Ta(CO) and represents the only well-defined zerovalent tantalum complex to be prepared by conventional laboratory methods. Two prior examples of homoleptic Ta complexes are known, Ta(benzene) and Ta(dmpe) , dmpe=1,2-bis(dimethylphosphano)ethane, but these have only been accessed via ligand co-condensation with tantalum vapor in a sophisticated metal-atom reactor. Consistent with its 17-electron nature, Ta(CNDipp) undergoes facile one-electron oxidation, reduction, or disproportionation reactions.

Crystal structure of hepta-kis-(2,6-di-methyl-phenyl isocyanide-κC)vanadium(I) iodide.

The title salt, [V(C9H9N)7](+)I(-) or [V(CNX-yl)7](+)I(-) (Xyl is 2,6-di-methyl-phen-yl), crystallized from tetra-hydro-furan at low temperatures after reacting (Et4N)(+)[V(CO)6](-), excess of CNXyl and iodine. The complex cation and the two crystallographically different iodide anions, each located on a different glide plane, are well separated in the crystal structure. The V(CN)7 core of the cation has the form of a distorted monocapped trigonal prism.

Crystal structure of (18-crown-6)potassium(I) [(1,2,3,4,5-η)-cyclo-hepta-dien-yl][(1,2,3-η)-cyclo-hepta-trien-yl]cobalt(I).

The reaction of bis-(anthracene)cobaltate(-I) with excess cyclo-hepta-triene, C7H8, resulted in a new 18-electron cobaltate containing two different seven-membered ring ligands, based on single-crystal X-ray diffraction. The asymmetric unit of this structure contains two independent cation-anion pairs of the title complex, [K(18-crown-6)][Co(η(3)-C7H7)(η(5)-C7H9)], where 18-crown-6 stands for 1,4,7,10,13,16-hexa-oxa-cyclo-octa-decane (C12H24O6), in general positions and well separated. Each (18-crown-6)potassium cation is in contact with the η(3)-coordinating ligand of one cobaltate complex.

Crystal structure of [(1,2,3,4,11,12-η)-anthracene]tris-(tri-methyl-stann-yl)cobalt(III).

The asymmetric unit of the title structure, [Co(η(6)-C14H10){Sn(CH3)3}3], contains two independent mol-ecules. Each anthracene ligand is η(6)-coordinating to a Co(III) cation and is nearly planar [fold angles of 5.4 (3) and 9.

Bis{bis-[1-meth-oxy-2-(2-meth-oxy-eth-oxy)ethane-κ(3) O,O',O'']sodium} 1,1,2,2-tetra-phenyl-ethane-1,2-diide.

Crystals of the title salt, [Na(C6H14O3)2]2(C26H20), were grown from a tetra-hydro-furan/diglyme/Et2O solvent mixture [diglyme is 1-meth-oxy-2-(2-meth-oxy-eth-oxy)ethane]. The cations and dianion are separated in the crystal structure, unlike in the other three structurally characterized dialkali metal tetra-phenyl-ethyl-ene salts. The asymmetric unit contains one [Na(diglyme)2](+) cation and one half of the [Ph2CCPh2](2-) dianion.

(η(4)-Cyclo-octa-tetra-ene)(η(8)-cyclo-octa-tetra-ene)iodido-tantalum(V).

The title complex, [Ta(η(4)-C8H8)(η(8)-C8H8)I], lies across a crystallographic mirror plane that includes the Ta(V) atom and the iodide ligand. One cyclo-octa-tetra-ene (cot) ring is η(4)-coordinating and is bis-ected by the mirror plane. The fold angle between the plane of the coordinating butadiene portion and the middle plane of the ring is 27.

Homoleptic 2,2'-bipyridine metalates(-I) of iron and cobalt, one cocrystallized with an anthracene radical anion and the other with neutral anthracene.

Homoleptic 2,2'-bipyridine (bipy) metalates of iron and cobalt have been synthesized directly from the corresponding homoleptic anthracene metalates. In the iron structure, bis[([2.2.

Bis(pyrene)metal complexes of vanadium, niobium and titanium: isolable homoleptic pyrene complexes of transition metals.

Reduction of VCl3(THF)3 (THF is tetrahydrofuran) and NbCl4(THF)2 by alkali metal pyrene radical anion salts in THF affords the paramagnetic sandwich complexes bis[(1,2,3,3a,10a,10b-η)-pyrene]vanadium(0), [V(C16H10)2], and bis[(1,2,3,3a,10a,10b-η)-pyrene]niobium(0), [Nb(C16H10)2]. Treatment of tris(naphthalene)titanate(2-) with pyrene provides the isoelectronic titanium species, isolated as an (18-crown-6)potassium salt, namely catena-poly[[(18-crown-6)potassium]-μ-[(1,2-η:1,2,3,3a,10a,10b-η)-pyrene]-titanate(-I)-μ-[(1,2,3,3a,10a,10b-η:6,7-η)-pyrene]], {[K(C12H24O6)][Ti(C16H10)2]}n. The first two compounds have very similar packing, with neighboring molecules arranged orthogonally to one another, such that aromatic donor-acceptor interactions are likely responsible for the specific arrangement.

(2.2.2-Cryptand)potassium tetra-carbonyl-cobaltate(-I).

The title salt, [K(C18H36N2O6)][Co(CO)4], is an example of a classical carbonyl-metalate. The asymmetric unit contains one cation and one tetrahedral anion, both in general positions. Based on comparison of the four carbonyl C-O bond lengths and C-Co-C angles, the anion is unperturbed by the cation, which is normal for an alkali metal fully encased by a cryptand cage.

(2.2.2-Cryptand)potassium tetra-kis-(η(2)-ethyl-ene)cobaltate(-I).

The title salt, [K(C(18)H(36)N(2)O(6))][Co(C(2)H(4))(4)], is one of only two known homoleptic ethyl-enemetalates. The cation and anion are well separated, which gives an unperturbed tetra-hedral anion as is expected for a formally Co(-I)d(10) metal center. The considerable elongation of the C=C bonds of the ethyl-ene ligands [average 1.

(18-Crown-6)potassium [(1,2,5,6-η)-cyclo-octa-1,5-diene][(1,2,3,4-η)-naph-tha-lene]-ferrate(-I).

The title salt, [K(C(12)H(24)O(6))][Fe(C(8)H(12))(C(10)H(8))], is the only known naphthalene complex containing iron in a formally negative oxidation state. Each (naphthalene)(1,5-cod)ferrate(-I) anion is in contact with one (18-crown-6)potassium cation via K⋯C contacts to the outer four carbon atoms of the naphthalene ligand (cod = 1,5-cyclo-octa-diene, 18-crown-6 = 1,4,7,10,13,16-hexa-oxacyclo-octa-deca-ne). When using the midpoints of the coordinating olefin bonds, the overall geometry of the coordination sphere around iron can be best described as distorted tetra-hedral.

Naphthalene and anthracene cobaltates(1-): useful storable sources of an atomic cobalt anion.

Reductions of CoBr(2) or cobaltocene by 3 equiv of potassium anthracene radical anion in tetrahydrofuran (THF) afford 60-80% yields of bis(anthracene)cobaltate(1-) (1), of interest as a readily accessible and quite labile source of spin-paired atomic Co(-). Although the unsolvated potassium salt of 1 is thermally unstable at 20 °C, the [K(18-crown-6)(THF)(2)](+) salt of 1 functions as a useful storable crystalline reagent for Co(-) in several reactions. Previously known classic cobaltates, [CoL(4)](-), for L = 1/2 (1,3-butadiene) (2), PF(3) (3), and P(OiPr)(3) (5), were obtained directly from 1 and structurally characterized for the first time.

([2.2.2]Cryptand-κ(6)O)potassium (η(4)-cyclo-octa-diene)bis-(η(2)-pyrene)cobaltate(1-) pentane hemisolvate.

The cation, anion, and solvent in the title compound, [K(C(18)H(36)N(2)O(6))][Co(C(8)H(12))(C(16)H(10))(2)]·0.5C(5)H(12), are well separated. The pentane solvent mol-ecules are found in channels along [100] and were modeled as disordered over crystallographic inversion centers.

Bis(η-naphthalene)-molybdenum(0).

The title compound, [Mo(C(10)H(8))(2)], was prepared from the naphthalene radical anion and MoCl(4)(thf)(2) (thf is tetra-hydro-furan). In the crystal, the mol-ecule is located on an inversion center. The Mo atom is equally disordered over two positions; the range of Mo-C distances is 2.