Square-planar structure

The phosphine complex Ru(dmpe)2 has been studied in matrices [62], Ru(diphos)2 (diphos = depe, dppe, (QFs P F P Fs ) has similarly been formed by photolysis of Ru(diphos)2H2 in low-temperature matrices. They probably have square planar structures and undergo oxidative addition with cobalt, C2H4 and hydrogen [63]. 

The 31P NMR spectrum in solution [47] is in accordance with a square planar structure (Figure 2.6). 

The double doublet corresponds to Pfi, with splitting owing to phosphorus A (cis) (/(P-P) 25 Hz) and rhodium (/(Rh-P) 172 Hz). The fluxional behaviour is consistent with a rapidly rearranging (at room temperature) square planar structure rather than a tetrahedral one (Figure 2.11). 

They have square planar structures corresponding bond lengths and vibrational frequencies are given in Table 3.3. 

AuMe2(acac) is being studied as a vehicle for laser CVD of gold films it has the expected square planar structure in the gas phase (Au—C 2.054 A Au-O 2.085 A) [168],... 

Complex (77) has been obtained by electrolysis of the respective Ni11 species (i 1/2= —0.78 V vs. Cp2Fe/Cp2Fe+ in DMF) and represents the first Ni111 complex with aliphatic thiolato donors that could be characterized crystallographically.300 The overall square planar structure is retained, but the Ni—N and Ni—S distances shorten by 0.023 A and 0.057 A, respectively, upon oxidation. While (77) is EPR-silent, its pyridine adduct shows an axial spectrum (g = 2.313, 2.281, 2.000) with N-hyperfine coupling of the z-component, indicative of a (r )1 ground state. 

A bis(stannyl)bis(phosphine)palladium complex has a twisted square planar structure and shows facile unimolecular twist-rotation.170... 

In a major breakthrough, Suzuki and co-workers29 demonstrated that a tetradentate ligand produced the bis -oxojdicopper II) complex (4) (each copper ion has a square planar structure,... 

Using a deprotonated hydroxyiminoamide ligand, Kruger and co-workers33 structurally characterized a discrete copper(III) compound (6). The square-planar structure is retained even in solution. Absorption and redox properties of this complex were also investigated. 

Cations that contain sulfur, selenium, and tellurium have also been studied for many years. One of the most common ions of this type is S42+, which has the following square planar structure. This is also the structure of Se42+ andTe42+, which have the dimensions shown. 

Although S42+, Se42+, andTe42+ ions have square planar structures, the ions S82+, Se82+, Te82+ exist as puckered rings ... 

Figure 2. The square planar structure that is obtained for the ground state of...

Thus, according to this alternate approach, C1F4 belongs to the VSEPR class AX4E2. Molecules of this type adopt a square planar structure. 

Square planar structures can show cis-trans isomerism. Examples are drawn following, with the m-isomer drawn on the left, and the /ra/w-isomer drawn on the right. 

The proposed mechanism is illustrated in Figure 8-5.60a Oxidative addition of the phenyl triflate to the palladium(0)-BINAP species A gives phenylpalla-dium triflate B. Cleavage of the triflate and coordination of 2,3-dihydrofuran on B yields cationic phenyl palladium olefin species C. This species C bears a 16-electron square-planar structure that is ready for the subsequent enantio-selective olefin insertion to complete the catalytic cycle (via D, E, F, and G). The base and catalyst precursor have profound effects on the regioselectivity and enantioselectivity. 

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