Pyramidality effect

Since the LUMO is n-antibonding, the kinetically controlled interaction of a donor molecule (HMPA) with the silicon leads to a decrease of multiple bonding between Cr and Si concomitant with a pyramidalization at the silicon atom. The resulting MSi bond distance and pyramidalization effect are strongly influenced by the respective substituents. 

Q54 Domperidone should not be used in patients receiving co-careldopa. Domperidone is commonly associated v/ith the occurrence of extra pyramidal effects. 

Domperidone is used in combination with antiparkinsonian drugs to counteract the nausea and vomiting caused by the latter. Since it does not readily cross the blood-brain barrier, it is not associated with extra-pyramidal effects and is less likely to cause dystonia than metoclopromide and phenothiazines. 

Aminoalkyl compounds, such as chlorpromazine and promazine, antagonize ai-adrenoreceptors, histamine Hi-receptors and muscarinic cholinergic receptors. The blockade of ai-adrenoreceptors and histamine Hi-receptors gives chlorpromazine a sedating profile, while a i-adrenoreceptor blockage also causes hypotension. The anticholinergic activity may cause dry mouth, urinary difficulties, and constipation, while, on the other hand, offsetting the liability to produce extra pyramidal effects. 

Piperazine compounds, such as trifluoperazine or fluphenazine, are the most selective dopamine receptor antagonists. They have the least sedating action and they are the most likely producer of extra pyramidal effects. 

Atypical antpipsychotics provoke fewer extra-pyramidal effects (less blockade of dopamine D -receptors in the nigrostriatal pathway). Nevertheless, extrapyramidal effects are seen, notably with high dose of risperidone (8-12 mg per day) and olanzapine (> 20 mg/day). 

In this contribution we focus on the structural data for Fe-Fe single bonds, from binuclear compounds to tetranuclear clusters that contain the [Fe2(CO)gJ fragment. In particular, we will show how the orientation of the ligands affects the Fe-Fe bond distance. First, we give a survey of the pyramidality effect on metal-... 

An interesting feature of the pyramidality effect is that the existence of axial li-... 

It is remarkable that pyramidality effects are observed for a large variety of M-M interactions, ranging from the quadruple bonds to single Rh or... 

Adverse reactions Gl complaints, headaches, dizziness, somnolence, sexual dysfunction, tremors less common reactions include breast tenderness or enlargement, extra-pyramidal effects, dystonia, fever, palpitations, weight gain or loss, rash, hives. Itching... 

The first-aid log is another important tool used in accident prevention. This type of log is not a requirement for OSHA. It is an in-house tool that, when studied carefully and acted on, will help reduce or eliminate accidents. If we believe in the pyramid effect, when we reduce the size of the bottom of the pyramid, which is reducing common minor incidents like first-aid incidents, this reduces the number of serious injuries. 

In this section we discuss the results of calculations on model Cr and Cr complexes with monodentate ligands. In this way, we can analyze the pyramidality effect without the geometric constraints imposed by the bridging ligand. As a ligand, we have chosen the ammonia molecule, to keep a comparable donor set as in the experimentally known amidinato complexes, and we explore the behavior of complexes with different number of ligands, [Cr2(NH3)2 ], where n = 2, 3, and 4. The calculated Cr-Cr distances are presented in Fig. 9 as a function of the... 

The second 5 bond in quintuply bonded [Cr2L4] complexes is stronger than the one present in quadruply bonded analogues, as a result of a symmetry-dictated s + d hybridization that introduces significant o character into the formally 8 bonding aig MO. The strength of the fifth bond is reflected in bond distances some 0.2 A shorter for Cr than for Cr complexes. Moreover, the inverted pyramidality effect on this orbital results in a smaller variability of the Cr-Cr quintuple bond distances as compared to the wide range of bond distances found for the quadruple bonds. 

A trial is reported of metiapine and chlorpromazine in the treatment of acute schizophrenia, given in maximum doses of 450 mg and 900 mg daily respectively. Unwanted effects of medication were of similar frequency in the 2 groups of patients with extra-pyramidal effects occurring in about 25% of patients. Several patients on metiapine showed tachycardia and this seemed to be dose-related (83 -). 

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