[(η⁵‐C₅Me₅)₂Fe₂S₄] and [(η⁵‐C₅Me₅)₂Co₂S₄], Two Novel Bis(pentamethylcyclopentadienylmetal) Complexes Rich in Sulfur

Abstract

6.57 (t, 2 H)], underwent the e x p e~t e d~~.~] photoisomerization to cyclobutanedione 7 [UV (methylcyclohexane): /2,,,=496 nm (110); IR (methylcyclohexane :CH2C12 1 : 1) v,,, = 1770, 1795 cm-'1 upon irradiation at 404 or 436 nm, with isosbestic behavior in the early stages of the reaction (305, 374 and 482 nm).Irradiation of 7 in methylcyclohexane at room temperature (A = 496 nm) resulted in its conversion into benzene, presumably via the intermediacy of 5. The quantum efficiency for this reaction is greater than the maximum value observed for formation of 7 from 6 . When the irradiation was performed at -8O"C, the spectrum of a new compound was obtained with maxima in the ultraviolet at 294, 282, 271 and 260 nm (sh). The extinction coefficients were of the order of 3000. The new compound is stable indefinitely at -80°C (cf. Fig. 1).16-1 1 L . A .1 2 .1 0 -0 8 . 06.O L .

Two Pseudopolymorphic Star‐Shaped Tetranuclear Co3+Compounds with Disulfide Anions Exhibiting Two Different Connection Modes and Promising Photocatalytic Properties

“…Each Co 3+ ion is surrounded by four S atoms of four different S 2 2− dumbbells and two N atoms of the amine ligands yielding a distorted CoS 4 N 2 octahedral environment as evidenced by the trans ‐angles around the Co 3+ centers varying from 168.87(3) to 177.42(7)° (Tables S1 and S2 in the Supporting Information for compound II ). Such deviations are not unusual and were also reported in literature 6. 7, 14 The CoS 4 N 2 octahedra each share two edges with neighbored octahedra leading to non‐bonding Co 3+ –Co 3+ separations of 3.249–3.291 Å, and the Co 3+ ions form a rectangular plane (mean deviation: 0.0002 Å).…”

“…For example, in [Cp 4 Co 4 (m 3 -S) 3 (m 3 -S 2 )] the CoÀSb onds are between 2.2003 and 2.2350 , [3] whereas in [(h 5 -C 5 Me 5 ) 2 Co 2 S 4 ]v alues in am ore narrow range, that is, 2.244-2.247,a re observed. [6] In all Co compounds with S 2 2À dianions [3][4][5][6][7][8][9][10] no CoÀSbond longer than 2.3 w as reported.…”

“…Such deviations are not unusuala nd were also reported in literature. [6,7,14] The CoS 4 N 2 octahedra each share two edges with neighbored octahedra leading to non-bonding Co 3 + -Co 3 + separations of 3.249-3.291 , and the Co 3 + ions form ar ectangular plane (mean deviation: 0.0002 ). The Co 3 + d 6 centers are in the low-spin state as expected.…”

“…[3,4] In the compound [SCo 3 (CO) 7 ] 2 S 2 the disulfide ion bridges four Co centers in the mode II d. [5] The mode Ib is found in the structure of [(h 5 -C 5 Me 5 ) 2 Co 2 S 4 ], which was synthesized in tolueneb y using [C 5 Me 5 (CO)Co] 2 and S 8 . [6] The structureso f [Co(m-S 2 )([15]aneN 4 )] 2 X 2 ([15]aneN 4 = 1,4,8,12-tetraazacyclopentadecane;X = BPh 2 ,C lO 4 )c ontain two S 2 2À ions bridging two Co atoms in the II bm ode to form aC o 2 S 4 heterocycle. [7] A heterometallic [AsCo 3 (S 2 )(S) 3 ]c ore in the compound [(C 5 Me 4 Et) 3 Co 3 AsS 5 ]I exhibitst he S 2 2À unit acting in the II cf ashion.…”

Reactivity studies on [Cp′Fe(μ-I)]2: nitrido-, sulfido- and diselenide iron complexes derived from pseudohalide activation

“… 25 From an organometallic point of view, metal chalcogenido clusters are generally prepared by the thermal reaction of elemental chalcogens with transition metal carbonyls such as [CpFe(μ-CO)(CO)] 2 . 26 The outcome of these reactions is not very predictable, but some control can be achieved by changing the steric demand on the Cp-ligands, whereby various iron chalcogenides such as [(η 5 -C 5 H 5 ) 4 Fe 4 S n ] ( n = 4–6), 27 [(η 5 -C 5 Me 5 ) 2 Fe 2 S 4 ], 28 [(η 5 -(Me 3 Si)C 5 H 4 ) 4 Fe 4 S 6 ], 29 [(η 5 -1,3-(Me 3 Si) 2 C 5 H 3 ) 2 Fe 2 S 4 ], 29 [(η 5 -C 5 H 5 ) 2 Fe 4 Se 4 ], 30 and [(η 5 -C 5 Me 5 ) 3 Fe 3 Se 8 ] 31 have been isolated. However, the facile and selective formation of [Cp′Fe(μ-S)] 2 ( 3 ) from 1 and KSCN provides the first organometallic model of the Rieske [2Fe–2S] cluster, whereas thermolysis of [Cp′Fe(CO)(μ-CO)] in the presence of S 8 only yields the disulfide-bridged compound [Cp′Fe(μ-S 2 )] 2 (see ESI † for details).…”