Ancillary groups

In a similar manner, imines 50 with various ancillary groups X, such as ethoxy-carbonyl, 2-pyridyl, or 2-thiazolyl, are also converted into lactams 51 in mod-erate-to-good yields (Eq. 24) [38]. The [2+2+1] lactam formation using a chiral substrate 52, ethylene, and CO quantitatively furnished the spiro lactam 53 (Eq. 25) [39]. The cycloaddition exclusively took place at the carbon-nitrogen double bond next to the oxazine oxygen atom, although 53 was obtained as a diastereomeric mixture. 

Aside from intercalators, a number of other tethered electroactive moieties can provide added functionality to nucleic acids. These moieties are often based on ferrocene chemistry [180-182] but others derived from quinones [176,183,184] have also emerged. Additionally, derivatives with altered linker and ancillary groups are used to make the functionalized nucleic acids electro chemically distinguishable [185-188], and thus compatible with identification methodologies that rely upon detection of sequence variants. Whilst some efforts have been directed at solid phase synthetic routes for probe production, others have focussed on construction of electroactive nucleotides ( electrotides ) compatible with enzymatic methods of incorporation into nucleic acids (Fig. 4). 

Ancillary groups. Finally it may be noted that the various substituents of the ligand may well carry chiral centres. This is indeed a traditional way of introducing a specific chirality into a ligand. Most fi equently the source will be an asymmetric carbon atom, but there are other possibilities. The propeller-like arrangement of phenyl groups in triphenylphosphane results in two possible enantiomers, and this chirality may influence the rest of the complex. 

Introduction of chirality in ancillary groups often acts by steric repulsion between different ligands, but the podates form an important exception. These multidentate ligands have two or more ligating strands attached to a template, and if this is chiral. 

The main building blocks of any LIF set-up incorporate (i) the laser system, (ii) the reaction environment, and (iii) the fluorescence detection system. In addition, various ancillary groups might be encountered, such as optical components to shape the incoming laser beam, and most likely some imaging optics for efficient collection of the fluorescence emission. Also, some laser monitoring equipment is likely, measuring the laser s power, and temporal, spectral and spatial profiles. 

Figure 2 Schematic depiction of a more sophisticated coordination complex consisting of bridging ligands joining two metal atoms in a dinuclear unit, together with the incorporation of property-oriented ancillary groups. The second coordination sphere corresponds to counterions or solvent molecules that present intermolecular interactions with the complex.

Ancillary groups Steric effects Solubility Optical and redox Chirality... 

A series of mesostructured aluminophosphate (AlPO)-based lamellar materials have been characterised by several solid-state NMR techniques. The average number of A1 atoms and identify the nature of other ancillary groups in the second coordination sphere for each P site was estimated. A combination of several dipolar coupling-based P/ Al double-resonance techniques e.g. TRAPDOR, REDOR, and HETCOR as well as H P CP can provide more detailed structural information regarding the local environments of P and A1 atoms in AlPO-based mesostructured materials, which is not readily available from straightforward P and Al MAS experiments. ... 

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