Ein- und zweikernige carbonylkomplexe des molybdäns mit α,ω-bis-(diphenylphosphino)-alkanen

Zwitterionic and Cationic Bis(phosphine) Platinum(II) Complexes: Structural, Electronic, and Mechanistic Comparisons Relevant to Ligand Exchange and Benzene C−H Activation Processes

“…Crabtree has previously suggested that the highest frequency CO vibration, presumed to be an a 1 vibration, in tetracarbonyl molybdenum complexes is a reasonable gauge of the relative electron-releasing/accepting character for a bidentate chelate . Reaction of the appropriate bisphosphine ligand 1 − 3 with Mo(CO) 6 in refluxing THF for 24−36 h provided the required species [[Ph 2 BP 2 ]Mo(CO) 4 ][ASN] ( 4 ), (Ph 2 SiP 2 )Mo(CO) 4 ( 5 ), and (dppp)Mo(CO) 4 ( 6 ), respectively (Scheme ). Measurement of their respective IR spectra in dichloromethane solution established a trend similar to that of the platinum system: The highest frequency CO vibration for anionic 4 is 2005 cm -1 whereas the same vibration for both 5 and 6 is 2018 cm -1 .…”

“…Deuterated chloroform, benzene, dichloromethane, acetonitrile, and acetone were purchased from Cambridge Isotope Laboratories, Inc. and were degassed by repeated freeze−pump−thaw cycles and dried over activated 3-Å molecular sieves prior to use. (COD)PtCl 2 , (COD)PtMeCl, (COD)PtMe 2 , (COD)Pt( 13 CH 3 ) 2 , (COD)PtMePh, (COD)PtPh 2 , Ph 2 PMe, Ph 2 PCH 2 Li(TMEDA), ASNBr, [Li(Et 2 O) 2 ][B(C 6 F 5 ) 4 ], [H(Et 2 O) 2 ][B(C 6 F 5 ) 4 ], [ n Bu 4 N][B(C 6 F 5 ) 4 ], (dppp)Mo(CO) 4 , (dppp)PtMe 2 ,14b and P(C 6 F 5 ) 3 were prepared by previously described methods. (dppp)PtPh 2 16 was prepared by reaction of (COD)PtPh 2 with dppp in THF solution.…”

Reaction of [Mo(CO)6] with Ph2P(CH2)6PPh2(dpph): the synthesis of [Mo(CO)3(dpphn)][dpphn = Ph2P(CH2)2CHCH(CH2)2PPh2] and trans-[Mo2(CO)8(µ-dpph)2] and the crystal structure of the latter

“…Three standard reflections were monitored every 2 h: variation on I was <5%. Of 6227 reflections measured (1.0 < 8 < 44.9'; h, k, 1 -12 to 12, &14, -17 to 16, respectively), 5884 were unique, giving 3866 observed [I >, 2.00 (1)]. An absorption correction was made according to experimental ty scans (maximum, minimum transmission factors = 0.999, 0.970).…”

trans-[Mo2(CO)8(μ-dpppe)2] [dpppe = Ph2P(CH2)5PPh2]

“…There are several reports concerning reactions between a,~o-diphosphines and Group 6B metal carbonyls: the monobridged dinuclear complexes [(CO)sM{Ph2P(CH2)5PPh2}M(CO)5] were prepared from [M(CO)6] and 0.5 molar equivalent of dpppe either in EtOCH2CH2OCH2CH2OH under reflux (M = Mo; Dietsche, 1966) or with Me3NO as initiator in CH3CN (114 = Cr, Mo and W; Hor, 1989). The dpphbridged bimetallic complex trans-[Mo2(CO)8(p~dpph)2] [dpph = Ph2P(CH2)6PPh2] (1) was prepared thermolytically from [Mo(CO)6] and dpph under reflux in toluene (Ueng & Hwang, 1991).…”