Reaction of [{Cr(cp)(CO)₃}₂](cp =η⁵-C₅H₅) with elemental phosphorus. Isolation of [Cr₂(cp)₂(P₅)] as a thermolysis product and its X-ray crystal structure

Abstract

The reaction of [{Cr(cp)(CO), },] (1) with 2 mol equivalents of P, in toluene at 90 "C produces a [Cr,(cp),(q5-P,)](5), the relative proportion of which is dependent on the duration of the reaction. This, coupled with thermolysis studies on (2)-( 4), demonstrates that these three complexes are the primary products of the reaction, whereas (5) arises mainly from the thermolysis of (2), which also yields (3) and [{Cr(cp)(CO),},] (6). Complex (5) has been isolated from a reaction of (1) with P, at 11 0 "C after ca. 5 h. A single-crystal X-ray diffraction study of ( 5) shows it to be a triple-decker sandwich complex with a cyclic P, ring bonded to t w o Cr(cp) groups. Crystal data: monoclinic, space group P2,/n, a = 7.921 (2), b = 15.04(1), c = 11.704(4) A, p = 104.08(2)", and Z = 4. The spectral features of complex (5) are also presented. mixture of [Cr2(cp),(Co),(~-rl2-P2)1 (21, [WCP) (CO),(rl3-PJl (3), [WCP) (co)2h(pd (4), and There is much current interest in the syntheses and reactivity of transition-metal complexes containing bare P atoms or aggregate^.'-^ In extending our studies on the reactions of the Cr-Cr dimer [(Cr(cp)(CO),),] (1) (cp = q5-C5H5) with main group elements,,g5 we have treated it with elemental phosphorus under mild reaction conditions and obtained high P3)] (3).6 In this paper, we describe conditions that led to the isolation of [Cr,(cp),(P,)] (5), together with evidence indicating that (5) arises from the thermolytic degradation of (2), (3), and a polyphosphidochromium complex [ { Cr(cp)-(CO)2}5(Plo)] (4). Mechanistic pathways for the formation of (3) and (5) and the X-ray crystal structure of (5) are also presented. yields of C C r 2 ( c ~) 2 ( C 0 ) 4 ( ~-~ 2-p2>1 (2) and [Cr(cp)(CO),(rl ,-

[MPy]+ and [MxPy]- Clusters Generated by Laser Ablation and Investigated by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

“…In contrast, the range and diversity of inorganic metal-phosphorus and polyphosphide compounds is impressive. − P 2 units may bridge two metals. , A triangular P 3 unit has been observed coordinated to Cp(CO) 2 Cr . P 4 species have been observed with a distorted tetrahedral geometry coordinated by up to four metals, , or as a square coordinated by four or five metals. , P 5 systems are often cyclic and planar 41,47-49 but ring opening and ring distortion have been observed .…”

Synthesis, Structure and Bonding in Pentagonal Bipyramidal Cluster Compounds Containing a cyclo-Sn5 Ring, [(CO)3MSn5M(CO)3]4− (M = Cr, Mo)

“…The LUMOs shown in Figure 5 suggest that the amplitude of the LUMO is indeed shifted towards the apical atoms in Tl 7− 7 compared to [(CO) 3 CrSn 5 Cr(CO) 3 ] 4− , justifying the rather different descriptions of bonding applied in the two cases. An even more extreme example of a trans-annular bond can be found in the P 5 -bridged clusters, CpCrP 5 CrCp and Cp * CrP 5 CrCp * and their one-electron reduced analogues (Figure 1e) [14,51]. The neutral Cp cluster has a Cr-Cr separation is 2.69(1) Å, considerably shorter than that in 1, and Hoffmann's analysis of the bonding [52] concludes that there is indeed Cr-Cr bonding present.…”

Metal-Mediated Degradation and Reaggregation of White Phosphorus

“…Cothermolysis of dinuclear chromium complexes [{Cp x Cr(CO) n } 2 ] [n=2, (CrϵCr); 3, (Cr-Cr)] with white phosphorus has been used by Goh and coworkers to generate a family of derivatives incorporating P 2 , P 3 and P 5 ligands (Scheme 7) [58,96]. Remarkably, the paramagnetic dichromium triple decker derivative [{Cp*Cr} 2 (m,h 5 -P 5 )] (72) has been the first cyclo-P 5 complex characterized by X-ray crystallography [94b].…”