Spectroscopic Data and Structures

Scheme 5 Carbene-Rh(I) complexes Table 2 Spectroscopic data and structural parameters of Rh-carbene complexes [2]...

This article is organized primarily according to the periodic table and secondarily with regard to the importance of substrates found to react with metal vapor atoms. Tables, lists, and figmes will display many of the known compounds prepared via the metal vapor-substrate cocondensation method and give further information about physical properties, chemical behavior, spectroscopic data, and structural details. 

Spectroscopic data and structural data for 140a reveal a typically 77-coor-... 

Several analogous tripodal (amido)zirconium compounds 202170 and 203171 were prepared earlier using salt metathesis. Only when X in compound 202 is small, such as Me, the spectroscopic data and structural considerations indicate all three F-donors at ortho-positions of the aryl rings are bonded to Zr, demonstrating the coordinative flexibility of the ancillary donor functions in the tripodal amido complexes. 

Figure 1.15. O2 adducts of (A) the heme/Cu site of HCOs (compound A) and (B and C) two heme/Cu analogs . Structure A is derived from resonance Raman spectroscopy, structure B (derived from 2cFeCu, Figure 1.14, Table 1.2) is based on resonance Raman and H NMR spectroscopic data and structure C is determined by single-crystal X-ray analysis counterion (BPh ) is omitted for clarity . Replication of both the distal and proximal environment in 2cFeCu was required to obtain the biologically relevant ferric-superoxide/Cu isomer of the O2 adduct, not the more common ferric-peroxo-Cu isomer.

One apparent discrepancy between the spectroscopic data and the crystal structure is that no spectroscopic signal has been measured for participation of the accessory chlorophyll molecule Ba in the electron transfer process. However, as seen in Figure 12.15, this chlorophyll molecule is between the special pair and the pheophytin molecule and provides an obvious link for electron transfer in two steps from the special pair through Ba to the pheophytin. This discrepancy has prompted recent, very rapid measurements of the electron transfer steps, still without any signal from Ba- This means either... 

It has been reported that concentrated H2SO4 (98%) promotes conversion of 3,5-dibromolevulinic acid 47 into 4-bromo-5-(bromomethylene)-2(5// )-furanones 48 (R = Br R = H) along with minor products, while similar treatment using 20% oleum gives the isomeric 5-(dibromomethylene)-2(5// )-furanone 49 (R = H R = Br) as the major product (63AJC165). Spectroscopic data and chemical structures were not provided for the minor substances, but the formation of the major product was explained on the basis of the enol-lactonization process followed by oxidation (63AJC165). 

The isolation of four terpenes from the bitter principles of Ginkgo by Furukawa in 19326 marked an important advance in the quest for the identification of the active constituents of Ginkgo extracts. A second major milestone was reached in 1967 when Nakanishi and his group reported their extensive and brilliant studies which permitted the structures of these compounds to be fully defined.4 On the basis of spectroscopic data and chemical reactivity... 

Counting NO as a three-electron donor, [IrCl(NO)(PPh3)2]+ is, therefore, a 16-electron species isoelectronic with Vaska s compound, isolable as a red crystalline hexafluorophosphate (m.p. 211°C, i/(N-0) 1870 cm-1) or similar perchlorate and tetrafluoroborate a trans-structure is indicated by spectroscopic data, and it is presumed to have a linear Ir-N-0 grouping. 

Iridium chemistry also holds a rare example of a monodentate guanidinate ligand. The monomeric parent amido complex Cp Ir(PMe3)(Ph)(NH2) cleanly undergoes an insertion reaction on treatment with diisopropylcarbodiimide (Scheme 153). Spectroscopic data and an X-ray structural analysis revealed the presence of a nonchelating guanidinate ligand. ... 

The natural products aristone, 190, bisaristone A, 191, and bisaristone B, 192, all contain an indoloindolizine unit within their polycyclic structures. These natural products have been isolated from the leaves and branches of the Australian mountain wine berry. Structural assignments are derived from spectroscopic data, and as yet no syntheses have been reported <1987JOC4527>. 

Treatment of a solution of 2-benzothiazolylthioacetyl hydrazide 386 in ethanol with carbon disulfide in the presence of potassium hydroxide gives the rearrangement product [l,2,4]triazolo[3,4- ]benzothiazole-3-thiol 387 (unreported yield) (Scheme 43). The structure of this compound was confirmed by its analytical and spectroscopic data, and confirmed by unequivocal synthesis from 2-benzothiazolhydrazine 388 under the same experimental conditions <2002MI3, 2002MI4>. 

The formation of a monomeric amidino complex has been reported for the reaction of rhenium pentachloride with di-isopropylcarbodiimid. A composition of [ReCl4(prop 2N2CCI)] was derived from elemental analysis, spectroscopic data and the crystal structure of the molybdenum analogue. " ... 

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