# The crystal structures of 6'-(4-chloro-phen-yl)- and 6'-(4-meth-oxy-phen-yl)-6a'-nitro-6a',6b',7',9',10',12a'-hexa-hydro-2,6',8'-spiro-[ace-naphthyl-ene-1,12'-chromeno[3,4-]indolizin]-2-one.
> クロモノ[3,4-]インドリジン誘導体2種の結晶構造解析：コンフォメーションと超分子構造の特徴


## Abstract

Two spiro-fused chromeno[3,4-]indolizine compounds bearing 4-chlorophenyl (I) and 4-methoxyphenyl (II) substituents were characterized by X-ray crystallography. The six-membered pyran and piperidine rings adopt envelope and chair conformations, respectively, while the five-membered pyrrolidine rings display twist conformations. Compound II contains two crystallographically independent molecules in the asymmetric unit. An intramolecular C–H···O hydrogen bond forming a seven-membered ring motif is present in all three molecular entities. Disorder was observed in the nitro group of I and in the methoxybenzene moiety of one molecule of II. Intermolecular C–H···O and C–H···Cl contacts in I generate chains along [010] that further assemble into layers, while C–H···π interactions reinforce the packing. In II, C–H···O bonds connect the two independent molecules into square four-membered units, which are further organized into a three-dimensional supramolecular framework through multiple C–H···π contacts.

## Bibliographic

- **Authors**: Syed Abuthahir S, NizamMohideen M, Viswanathan V, Velmurugan D, Nagasivarao J
- **Journal**: Acta Crystallogr E Crystallogr Commun
- **Year**: 2019 (2019-02-01)
- **PMID**: [30800454](https://pubmed.ncbi.nlm.nih.gov/30800454/)
- **DOI**: [10.1107/S2056989019000422](https://doi.org/10.1107/S2056989019000422)
- **PMC**: [PMC6362674](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6362674/)
- **Study type**: other
- **Delivery route**: not specified
- **Effect reported**: not assessed

## Delivery context

The delivery route is not clearly identifiable from this paper. For hydrogen intake, inhalation is the most efficient route; inhalation, however, carries explosion risk (empirical LFL of 10%; high-concentration devices are not recommended).

## Safety notes

The delivery route is not clearly identifiable from this paper. For hydrogen intake, inhalation is the most efficient route; inhalation, however, carries explosion risk (empirical LFL of 10%; high-concentration devices are not recommended).

See also:
- [Inhalation concentration and LFL / UFL](https://h2-papers.org/en/safety-notes/inhalation-concentration)
- [Consumer Affairs Agency accident cases](https://h2-papers.org/en/safety-notes/accident-cases)

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> **Cite as**: H2 Papers — PMID 30800454. https://h2-papers.org/en/papers/30800454
> **Source**: PubMed PMID [30800454](https://pubmed.ncbi.nlm.nih.gov/30800454/)