Molybdenum carbonyl derivatives of catenated rings and chains of CH3As and C6H5As units. Synthesis and structural characterization of [cyclo-(CH3As)10Mo2(CO)6], [cyclo-(C6H5As)9Mo2(CO)6], and [catena-(C6H5As)8Mo2(CO)6]

Abstract

227ChemInform Abstract Reactions of Mo carbonyl compounds (I) or (IV) with the homoatomic ring compounds (II) or (V) in sealed tubes in toluene, produce clusters containing catenated RAs units. Neither the products nor yields are significantly dependent on which metal precursor compound is used, but are strongly dependent on the R at As. With (II), in the absence of O2, the only isolable product is (III), which crystallizes in the space group Pnnm with Z=2. In reactions with (V) the products obtained depend on the reaction conditions. (VI) (space group P21/c, Z=4) is obtained at 70 rc C and can be converted to (III) (toluene, 120 rc C, 24 h, 72% yield), which is directly obtained at 120 rc C. The catena-complex (VII) crystallizes in the space group P21/n with Z=4.

Octabromocyclohexaarsenate, [As6Br8]2⊖

“…The arenecarboxyl radicals were generated by laser flash photolysis of their parent peroxides and were detected in the absorption mode. [7] Statements to this effect can be found in several reviews [I] [lo] Very dilute solutions of 1 (typically 1-3 mg, to avoid crystallization) in cyclopropane (ca. 0.5 mL) were sealed in 4 mm 0.d.…”

Group-6 Carbonyl Complexes of Methylarsathiane Rings,cyclo-(CH3AsS)n(n= 4−6). Synthesis and Structural Characterization of [Cr(CO)5-η1-cyclo-(CH3AsS)4], [Cr(CO)3-η3-cyclo-(CH3AsS)5], and [W(CO)3-η3-cyclo-(CH3AsS)6]

“…The As−S−As and the S−As−S bond angles are found to be considerably smaller than the C−C−C bond angles in cyclodecane (av. 116.7°) 33 but slightly larger than in [Mo 2 (CO) 6 - η 6 -cyclo(CH 3 As) 10 ] (96.1°) ,− A slight elongation of the As−S bonds (2.307(3) and 2.297(3) Å) for the coordinated sulfur, S(2)−As(1) and S(2)−As(2), is observed.…”

“…We have previously studied reactions of cyclo- polyarsines, cyclo- (RAs) n , − with metal carbonyls. − West and co-workers also reported similar reactions. − One of the striking features of complexes formed from these homocyclic systems with transition-metal carbonyls is the variety of complexes containing arsenic chain and ring structures that can be derived from them . The products of cyclo- (RAs) n reactions can be broadly classified as products with intact rings, in which the ring retains its original size or expands, products in which the rings open and bridge two metal centers, and products in which the arsenic atoms lose some or all of their organic substituents and enter the complexes as naked arsenic atoms.…”

Host–Guest Chemistry – p-Block Systems

“…77,78 This flexibility is consistent with the lower bond energy of the As-As single bond (146 kJ mol À1 ) compared to P-P (201 kJ mol À1 ). 78 Solid-state materials in which encapsulation of metal centers occurs by rings of bare group 15 and 16 atoms are also relevant to the concept of host-guest chemistry in this area. 78 Solid-state materials in which encapsulation of metal centers occurs by rings of bare group 15 and 16 atoms are also relevant to the concept of host-guest chemistry in this area.…”