John E. Ellis

University of Minnesota Duluth, Duluth, Minnesota, United States

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Publications (132)784.91 Total impact

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    Mikhail E Minyaev · John E Ellis
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    ABSTRACT: 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. This compound is of inter-est as the first isolable homoleptic seven-coordinate vanadium analog of the 18-electron [V(CO)7](+) monocation.
    Preview · Article · Apr 2015
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    William W. Brennessel · John E. Ellis
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    ABSTRACT: The reaction of bis­(anthracene)cobaltate(−I) with excess cyclo­hepta­triene, 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(η3-C7H7)(η5-C7H9)], where 18-crown-6 stands for 1,4,7,10,13,16-hexa­oxa­cyclo­octa­decane (C12H24O6), in general positions and well separated. Each (18-crown-6)potassium cation is in contact with the η3-coordinating ligand of one cobaltate complex. Each η3-coordinating ligand behaves as an allylic anion whose exo-diene moiety is bent away from the allylic plane, and thus is not involved directly in the bonding. The metal-coordinating portions of the anionic η5 ligands are planar and one of these ligands is modeled as disordered over two positions, with occupancy ratio 0.699 (5):0.301 (5), such that one orientation is rotated by one carbon atom with respect to the other. The diffraction intensities were integrated according to non-merohedral twin law [-1 0 0/0 -1 0/0.064 0 1], a 180° rotation about reciprocal lattice axis [001], and the masses of the twin domains refined to equal amounts. As both ligands are formally coordinated as anions, the cobalt atom is best considered to be CoI. This compound is of inter­est as the first to possess cyclo­hepta­trienyl and cyclo­hepta­dienyl ligands in an anionic metal complex.
    Preview · Article · Mar 2015
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    William W Brennessel · John E Ellis
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    ABSTRACT: 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 9.7 (3)°], as would be expected for its behaving almost entirely as a donor to a high-oxidation-state metal center. The slight fold in each anthracene ligand gives rise to slightly longer Co-C bond lengths to the ring junction carbon atoms than to the other four. Each Co(III) cation is further coordinated by three Sn(CH3)3 ligands, giving each mol-ecule a three-legged piano-stool geometry. In each of the two independent mol-ecules, the trio of SnMe3 ligands are modeled as disordered over two positions, rotated by approximately 30%, such that the C atoms nearly overlap. In one mol-ecule, the disorder ratio refined to 0.9365 (8):0.0635 (8), while that for the other refined to 0.9686 (8):0.0314 (8). The mol-ecules are well separated, and thus no significant inter-molecular inter-actions are observed. The compound is of inter-est as the first structure report of an η(6)-anthracene cobalt(III) complex.
    Preview · Article · Nov 2014 · Acta Crystallographica Section E Structure Reports Online
  • William W Brennessel · John E Ellis
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    ABSTRACT: 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[([2.2.2]cryptand)potassium(I)] tris­(2,2'-bi­pyridine)­fer­rate(-I) anthracene(-I), [K(C18H36N2O6)]2[Fe(C10H8N2)3](C14H10), the asymmetric unit contains one potassium complex cation in a general position, the Fe center and one and a half bipy ligands of the ferrate complex on a crystallographic twofold axis that includes the Fe atom, and one half of an anthracene radical anion whose other half is generated by a crystallographic inversion center. The cations and anions are well separated and the geometry about the Fe center is essentially octa­hedral. In the cobalt structure, ([2.2.2]cryptand)potassium(I) bis­(2,2'-bi­pyridine)­cobaltate(-I) anthracene hemisolvate tetra­hydro­furan (THF) disolvate, [K(C18H36N2O6)][Co(C10H8N2)2]
    No preview · Article · Aug 2014 · Acta crystallographica. Section C
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    ABSTRACT: 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. The asymmetric unit contains a half-occupancy metal center η6-coordinated to one pyrene ligand, with the full M(pyrene)2 molecule generated by a crystallographic inversion center. In the titanium compound, the cations and anions are in alternating contact throughout the crystal structure, in one-dimensional chains along the [101] direction. As in the other two compounds, the asymmetric unit contains a half-occupancy Ti atom η6-coordinated to one pyrene ligand. Additionally, the asymmetric unit contains one half of an (18-crown-6)potassium cation, located on a crystallographic inversion center coincident with the K atom. The full formula units are generated by those inversion centers. In all three structures, the pyrene ligands are eclipsed and sandwich the metals in one of two inversion-related sites. These species are of interest as the first isolable homoleptic pyrene transition metal complexes to be described in the scientific literature.
    No preview · Article · Aug 2014 · Acta crystallographica. Section C
  • Source
    Mikhail E Minyaev · John E Ellis
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    ABSTRACT: 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. The latter lies on a twofold rotation axis. C-C bond-length redistribution displays that excessive electron density of the dianion is predominantly located at the C atoms of a former double bond and at all eight ortho positions. The studied crystal was a twin, with the ratio of two major components being 0.2143 (9):0.7857 (9). The twin operation is a twofold rotation around the a axis.
    Preview · Article · Jul 2014 · Acta Crystallographica Section E Structure Reports Online
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    ABSTRACT: 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 27.4 (4)°. An additional minor fold angle of 9.3 (7)° exists between the final plane in the ring and the middle plane. The other cot ring is η(8)-coordinating and is also cut by the mirror plane. In this case, the ring is disordered over the mirror plane, and one position is modeled with appropriate restraints and constraints with respect to distances, angles and displacement parameters (the second position is generated by symmetry). This ring is nearly planar, with an r.m.s. deviation of only 0.05 Å when all eight C atoms are included in the calculation. Pairs of inter-molecular η(8)-cot rings are parallel stacked and slightly off center, with a centroid-centroid distance of 3.652 Å. No other significant inter-molecular inter-actions are observed. The compound is of inter-est as the first structurally characterized mixed halogen-cot complex of the group 5 metals and contains the longest terminal Ta-I distance [3.0107 (5) Å] reported to date.
    Preview · Article · Jul 2014 · Acta Crystallographica Section E Structure Reports Online
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    William W Brennessel · John E Ellis
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    ABSTRACT: The title salt, [K(C 18 H 36 N 2 O 6 )][Co(CO) 4 ], is an example of a classical carbonylmetalate. 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.
    Preview · Article · May 2014 · Acta Crystallographica Section E Structure Reports Online
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    ABSTRACT: This chapter presents syntheses of Ti(CO)3(DMPE)2, DMPE = 1,2-bis(dimethylphosphano)ethane, and [Ti(CO)6]2-. The former compound is of interest because it is the first isolable and well-characterized derivative of the unknown Ti(CO)7 and is a key precursor to other zero-valent titanium carbonyls. All operations are conducted under an atmosphere of 99.9% argon or 99.5% carbon monoxide. Standard Schlenk techniques are employed with a double-manifold vacuum line. The chapter discusses the procedures and properties of bis(1,2-bis(dimethylphosphano)ethane) tricarbonyltitanium(0) and 18-crown-6 bis(acetonitrile)potassium hexacarbonyltitanate(2 -).
    No preview · Article · Apr 2014 · Inorganic Syntheses
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    William W Brennessel · John E Ellis
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    ABSTRACT: 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. The naphthalene fold angle between the plane of the iron-coordinating butadiene unit and the plane containing the exo-benzene moiety is 19.2 (1)°.
    Preview · Article · Oct 2012 · Acta Crystallographica Section E Structure Reports Online
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    William W Brennessel · John E Ellis
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    ABSTRACT: 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 1.401 (6) Å], relative to that of free ethyl-ene (1.333 Å), is consistent with metal→π* back-bonding models. One arm of the 2.2.2-cryptand (4,7,13,16,21,24-hexa-oxa-1,10-diaza-bicyclo-[8.8.8]hexa-cosa-ne) complexant is disordered and was modeled over two positions with a refined occupancy ratio of 0.559 (2):0.441 (2). In the crystal, the cationic K(2.2.2-cryptand) units are linked via C-H⋯O hydrogen bonds, forming inversion dimers. There are no other significant inter-molecular inter-actions in the crystal structure.
    Preview · Article · Oct 2012 · Acta Crystallographica Section E Structure Reports Online
  • Source
    William W. Brennessel · John E. Ellis
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    ABSTRACT: The title salt, [K(C18H36N2O6)][Co(C2H4)4], is one of only two known homoleptic ethyl­enemetalates. The cation and anion are well separated, which gives an unperturbed tetra­hedral anion as is expected for a formally Co−I d10 metal center. The considerable elongation of the C=C bonds of the ethyl­ene ligands [average 1.401 (6) Å], relative to that of free ethyl­ene (1.333 Å), is consistent with metal→π* back-bonding models. One arm of the 2.2.2-cryptand (4,7,13,16,21,24-hexa­oxa-1,10-diaza­bicyclo­[8.8.8]hexa­cosa­ne) complexant is disordered and was modeled over two positions with a refined occupancy ratio of 0.559 (2):0.441 (2). In the crystal, the cationic K(2.2.2-cryptand) units are linked via C—H⋯O hydrogen bonds, forming inversion dimers. There are no other significant inter­molecular inter­actions in the crystal structure.
    Preview · Article · Sep 2012 · Acta Crystallographica Section E Structure Reports Online
  • William W Brennessel · John E Ellis
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    ABSTRACT: 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. Anion 3 is noteworthy because it appears to possess the shortest known Co-P distance, av = 2.012(4) Å. Although the naphthalene analogue of 1 is not yet available as a pure substance, low-temperature reductions of CoBr(2) or cobaltocene by naphthalene radical anion in the presence of 1,5-cyclooctadiene (COD) afford variable yields (80-90% from CoCp(2)) of (naphthalene)(COD)cobaltate(1-) (10). Ready displacement of naphthalene in 10 by L = 1,3-butadiene, 2,2'-bipyridine, and COD occurs to give good yields of the respective [Co(L)(COD)](-), all of which have been structurally characterized. Both ligands in 10 are displaced by tert-butylisocyanide to afford [Co(CNtBu)(4)](-) (16), the first isolable and structurally characterized homoleptic alkylisocyanometalate. The molecular structure of 16 shows unprecedented bending of the isocyanides, av C-N-C = 137(2)°, for homoleptic isocyanide complexes.
    No preview · Article · Aug 2012 · Inorganic Chemistry
  • Source
    William W Brennessel · John E Ellis
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    ABSTRACT: 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. Using the mid-points of the coordinated olefins, the angle between the C(py)/C(py)-Co-C(py)/C(py) and the C(cod)/C(cod)-Co-C(cod)/C(cod) planes (py is pyrene and cod is cyclo-octa-diene) is 67.6 (2)°. Thus, the overall geometry of the coordination sphere around cobalt is best described as distorted tetra-hedral.
    Preview · Article · Jul 2012 · Acta Crystallographica Section E Structure Reports Online
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    Mikhail E Minyaev · John E Ellis · William J Wolf
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    ABSTRACT: 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 2.2244 (19)-2.3400 (17) Å for both components of the disorder.
    Preview · Article · Feb 2012 · Acta Crystallographica Section E Structure Reports Online
  • John E. Ellis
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    ABSTRACT: This chapter discusses highly reduced metal–carbonyl anions. In the unusually effective reducing medium of sodium-hexamethylphosphoramide (HMPA), [Mn(CO)5]– underwent facile reduction to form a golden yellow to yellow brown solution. It is often important to use solutions rather than slurries of trianion salts to minimize the formation of side products during the reactions of these materials with electrophiles. Infrared spectra of Na3[M(CO)4] as solutions in HMPA or as mineral oil mulls of the solid are quite similar in terms of peak positions. Protonation reactions of [M(CO)4]3– and most of the known reactions of Na3[Re(CO)4] are examined. Perhaps the most persuasive chemical evidence for the existence of the monohydrides of manganese and rhenium is their high-yield conversion to corresponding dihydrides, which can be isolated as relatively stable crystalline solids. The tricesium salt was obtained as an orange–brown powder and the corresponding trirubidium compound was isolated as a golden to red–brown shiny microcrystalline substance. The materials are especially prone to violent decomposition when they are even gently scraped off of a fritted glass disk with a metal spatula. One very important and obvious limitation of this reductive labilization method is that the ligand to be expelled should not be susceptible to reduction either in a coordinated or free state.
    No preview · Article · Jul 2010 · ChemInform
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    ABSTRACT: ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
    No preview · Article · Apr 2010 · ChemInform
  • Victor J Sussman · John E Ellis
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    ABSTRACT: For the first time [N(PPh(3))(2)](+), or [PPN](+), has been shown to undergo an irreversible reaction with a transition metal complex under ambient conditions and affords a product containing a unique structural motif in which two phenyl groups on one PPh(3) substituent of [PPN](+) are ortho-metallated, while the third phenyl ring is hydrogenated to provide a tantalum bound 1,3-cyclohexadiene group.
    No preview · Article · Dec 2008 · Chemical Communications
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    ABSTRACT: Positives zu Anionen: Kohlenwasserstoffkomplexe von Hf in negativen Oxidationsstufen wurden erstmals ausgehend von Tris(polyaren)hafnaten(2−) (Polyaren=Anthracen oder Naphthalin) als Quelle für Hf2− erhalten (siehe Schema, cot=1,3,5,7-Cyclooctatetraen). Die Synthese der Tris(anthracen)metallate(2−) von Ti und Zr vervollständigte eine beispiellose Triade von Tris(aren)metallkomplexen.
    No preview · Article · Oct 2008 · Angewandte Chemie International Edition
  • Jessica M. Allen · John E. Ellis
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    ABSTRACT: Oxidation of [CpTi(CO)4]− by I2, Ph3SnCl, and Me3SnCl in the presence of four equivalents of CNXyl, Xyl=2,6-dimethylphenyl, affords unprecedented titanium tetraisocyanide complexes, [CpTi(CNXyl)4E], E=I, SnPh3, SnMe3. These have been isolated and characterized by spectroscopic methods as well as single-crystal X-ray crystallography. A by-product of the iodine reaction was the Ti(III) complex, [CpTi(CNXyl)2I2], which was also characterized by X-ray crystallography.
    No preview · Article · Apr 2008 · Journal of Organometallic Chemistry

Publication Stats

2k Citations
784.91 Total Impact Points

Institutions

  • 1975-2015
    • University of Minnesota Duluth
      • Department of Chemistry and Biochemistry
      Duluth, Minnesota, United States
  • 2002
    • Michigan Technological University
      • Department of Chemistry
      Хаутон, Michigan, United States
  • 1999
    • Massachusetts Institute of Technology
      Cambridge, Massachusetts, United States
  • 1992
    • University of Delaware
      • Department of Chemistry and Biochemistry
      Ньюарк, Delaware, United States