Octachlorodimolybdate(II) ion. Species with a quadruple metal-metal bond

Brenčíč, J. V.; Cotton, F. Albert

doi:10.1021/ic50071a002

Cited by 107 publications

(34 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Octahalodimolybdate tetraanions, [Mo2X8] 4-, are known for X = C1 (Brencic & Cotton, 1969) and Br (Brencic, Dobcnik & Segedin, 1974) but have never been reported for X = I. The above complexes were prepared by interaction of the acetate complex Mo2(OOCCH3)4 or the sulfate complex (NH4)4Mo2(SO4)4.2H20 with aqueous HX solutions.…”

Section: Commentmentioning

confidence: 99%

“…Data collection: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1985 (Brencic & Cotton, 1969) and Br (Brencic, Dobcnik & Segedin, 1974) (Glicksman & Walton, 1978). There are, however, numerous dimeric complexes of the Mo2X4L,4 type where X = I (Cotton & Walton, 1982) and the hexaiodo complexes [Cat]2[MOEI6(H20)2] (Cat = pyH ÷, picH*) are also known (Brencic & Segedin, 1978;Brencic & Golic, 1977 (Stensvad, Helland, Babich, Jacobson & McCarley, 1978), treatment of Mo2(OOCCH3)4 with HI (Glicksman & Walton, 1978), and now reaction of [Mo2(MeCN)8] 4+ with I-} invariably generate the same [MO4Ill] 2-cluster instead.…”

mentioning

confidence: 99%

See 1 more Smart Citation

A Tetranuclear Butterfly Cluster of Molybdenum, [PPh4]2[Mo4I11]

Gordon¹,

Poli²

1995

Acta Crystallogr C

View full text Add to dashboard Cite

Bis (tetraphenylphosphonium) undecaiodotetramolybdate, 2[PPh4]+[Mo,I11] 2-, was obtained by treating [Mo2(MeCN)8] 4+ with PPN+I -in dichloromethane. The four Mo atoms of the anion adopt a 'butterfly' arrangement which can be viewed as a portion of an octahedron with two missing mutually cis vertices. Ten of the eleven I atoms are located at the vertices of a cube in which the ideal octahedron would be inscribed; two of them cap the two triangular faces of the Mo4 buttefly, four bridge the edges and four are terminally coordinated to the metal atoms. The eleventh I atom bridges the two 'wing-tip' metal atoms. The metal-metal distances for four edges of the butterfly wings are in the range 2.533 (3)-2.547 (3) ,A,, whereas the 'hinge' edge is slightly longer [2.688 (3) A,] and the separation between the two wing tips is 3.051 (3) ~. CommentOctahalodimolybdate tetraanions, [Mo2X8] 4-, are known for X = C1 (Brencic & Cotton, 1969) and Br (Brencic, Dobcnik & Segedin, 1974) but have never been reported for X = I. The above complexes were prepared by interaction of the acetate complex Mo2(OOCCH3)4 or the sulfate complex (NH4)4Mo2(SO4)4.2H20 with aqueous HX solutions. On the other hand, the analogous interaction between Mo2(OOCCH3)4 and HI affords, after treatment with ["Bu4N]I, the salt [nBu4N]2[MO4Ill] (Glicksman & Walton, 1978). There are, however, numerous dimeric complexes of the Mo2X4L,4 type where X = I (Cotton & Walton, 1982) and the hexaiodo complexes [Cat]2[MOEI6(H20)2] (Cat = pyH ÷, picH*) are also known (Brencic & Segedin, 1978;Brencic & Golic, 1977 (Stensvad, Helland, Babich, Jacobson & McCarley, 1978) and another with the [AsPh4] ÷ counterion (Cotton & Poli, 1988), but neither was reported in full. We report here the full details of the structure of the tetraphenylphosphonium salt, [PPhn]2[Mo4I~I], which is not isomorphous with the previously described [AsPh4] ÷ salt and does not have the twinning problems encountered in that case.The compound crystallizes in the centrosymmetric space group P1 with both cations and the dianion in general positions. The two independent tetraphenylphosphonium cations are similar to each other. The average P--C bond lengths for the two ions are 1.78 (2) and 1.82 (3)/~. The values of the C--P--C angles are all very close to the expected tetrahedral value, being in the range 107-112 ° with averages of 109.7(10) and 109.5 (20) ° for the two ions. Other features of these cations are normal and do not merit further discussion.A view of the [Mo4I]]] 2-anion is shown in Fig. 1. The I atoms have been labeled according to the number of the Mo atom(s) to which they are bonded. For instance, 1(23) is bonded to atoms Mo(2) and Mo(3), etc. I atoms with one-digit numbers are thus terminal ligands, those with two-digit numbers are doubly bridging and those with three-digit numbers are triply bridging. The best geometical description of this ion is based on the geometry of the well known family of octahedral clusters [Mo6X8] 4+, as described for the tetra-n-butylammonium salt of t...

show abstract

Section: Commentmentioning

confidence: 99%

mentioning

confidence: 99%

A Tetranuclear Butterfly Cluster of Molybdenum, [PPh4]2[Mo4I11]

Gordon¹,

Poli²

1995

Acta Crystallogr C

View full text Add to dashboard Cite

show abstract

“…In fact, no example of metal-metal double bonds without bridging ligands existed until recently (excluding or- ganometallic and metal carbonyl species). These structural differences among the various bond multiplicities have precluded a systematic study of direct metal-metal interaction over the entire range of bond orders.The conformational restriction imposed by metal-metal bonding is an important property that has been used to help assign bond orders of M2L8 systems (8,9,(14)(15)(16)(17). From a group theoretical analysis, the o and pair of degenerate r bonds place no angular constraint on the orientation of the two ML4 fragments (18).…”

mentioning

confidence: 99%

“…The conformational restriction imposed by metal-metal bonding is an important property that has been used to help assign bond orders of M2L8 systems (8,9,(14)(15)(16)(17). From a group theoretical analysis, the o and pair of degenerate r bonds place no angular constraint on the orientation of the two ML4 fragments (18).…”

mentioning

confidence: 99%

Systematic variation of metal—metal bond order in metalloporphyrin dimers

Collman

Barnes

Woo

1983

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

A general method for synthesizing a novel class of metalloporphyrin dimers containing unbridged metal-metal bonds is presented. By choosing the appropriate metal, the bond order in these dimers can be varied systematically. The synthesis and characterization of osmium(l) and molybdenum(II) porphyrin dimers containing the respective metal-metal double and quadruple bonds are described. A simple molecular orbital treatment that accounts for the metal-metal bonding, spin state, and geometry in these complexes is discussed.Binuclear transition metal complexes containing multiple metalmetal bonds were prepared as early as 1844 (1). However, this area remained dormant for the following 120 years because the true constitution of these compounds was not understood. It was not until Cotton (2-5) and Robinson (6,7) recognized and correctly determined the single-crystal x-ray structures of a number of complexes containing multiple metal-metal bonds that this field began to evolve. One of the key developments of this seminal period was the delineation of the quadruple bond.The molecular orbital diagram conceived by Cotton (8, 9) for a quadruply bonded M2L8 system remains qualitatively valid and is shown in Fig. 1A. From symmetry considerations, the energy levels for a staggered geometry can be derived and are shown in Fig. 1B. The utility of these molecular orbital schemes is apparent because they account for the ground state geometry, spin state, and bond order of a number of M2L8 systems solely on the basis of the total number of d electrons. A classic example is the octachlorodirhenate dianion, Re2CI82-, which has been shown to possess D4h symmetry by an x-ray crystal structure determination (3). The eight d electrons of this complex populate the four lowest molecular orbitals in Fig. 1A, resulting in a quadruply bonded, diamagnetic species with an eclipsed geometry. More significantly, these molecular orbital diagrams predict that bond orders from 0.5 to 4.0 are possible for an M2L8 system.The variation of bond order by changing the d electron count has been demonstrated by the preparation of Re2Cl6L2 (10) and Re2Cl4L4 (11), in which L is triethylphosphine. The former complex contains eight d electrons and by convention possesses a quadruple bond, whereas the latter has a formal triple bond arising from its d10 configuration. However, only a partial range of bond orders has been realized in M2L8 systems because the presence of labile ligands can result in structural reorganization to species of higher nuclearity (12) or bridged complexes (13). The bridging mode in such species introduces a further complication by masking the presence of metal-metal bonding and bond order. In fact, no example of metal-metal double bonds without bridging ligands existed until recently (excluding or- ganometallic and metal carbonyl species). These structural differences among the various bond multiplicities have precluded a systematic study of direct metal-metal interaction over the entire range of bond orders.The conformational r...

show abstract

“…Physikalische Daten der Verbindungen ( Z a ) , (4), (4).HC1, (6).HC1, (7) und (8). Bei den friiheren Strukturanalysen wurde eine 5m2-(Dsh-) Symmetrie zugrunde gelegt.…”

unclassified

Röntgenographischer Beweis der oxidativen Addition an eine Metall‐Metall‐Vierfachbindung durch vollständige Strukturanalyse von [Mo₂Cl₈H]³⁻

Bino

Cotton

1979

Angewandte Chemie

Self Cite

View full text Add to dashboard Cite

C1 N=C= c1.,ClWie Trichlorvinyli~ocyanat[~~ sind (2) und ( 4 ) wertvolle 1,3-biselektrophile Reagentien speziell fur Heterocyclisierungen. Beispielsweise setzt sich (212) (R= CH3) rnit Benzamidin in 80% Ausbeute zum substituierten Triazin (6) um, und ( 4 ) ergibt mit rn-Methoxyanilin das Chinazolin (7) (50%) und mit Hydrazinhydrat das Triazol (8) (55%). In Tabelle 1 sind einige physikalische Daten zusammengestellt. Angew. Chem. 91 (1979) N r 4 0044-8249J79jO404-0356 S 02.50/0

show abstract

Octachlorodimolybdate(II) ion. Species with a quadruple metal-metal bond

Cited by 107 publications

References 0 publications

A Tetranuclear Butterfly Cluster of Molybdenum, [PPh4]2[Mo4I11]

A Tetranuclear Butterfly Cluster of Molybdenum, [PPh4]2[Mo4I11]

Systematic variation of metal—metal bond order in metalloporphyrin dimers

Röntgenographischer Beweis der oxidativen Addition an eine Metall‐Metall‐Vierfachbindung durch vollständige Strukturanalyse von [Mo₂Cl₈H]³⁻

Contact Info

Product

Resources

About

Octachlorodimolybdate(II) ion. Species with a quadruple metal-metal bond

Cited by 107 publications

References 0 publications

A Tetranuclear Butterfly Cluster of Molybdenum, [PPh4]2[Mo4I11]

A Tetranuclear Butterfly Cluster of Molybdenum, [PPh4]2[Mo4I11]

Systematic variation of metal—metal bond order in metalloporphyrin dimers

Röntgenographischer Beweis der oxidativen Addition an eine Metall‐Metall‐Vierfachbindung durch vollständige Strukturanalyse von [Mo2Cl8H]3−

Contact Info

Product

Resources

About

Röntgenographischer Beweis der oxidativen Addition an eine Metall‐Metall‐Vierfachbindung durch vollständige Strukturanalyse von [Mo₂Cl₈H]³⁻