Syntheses and crystal structures of [Ir(III){C(CHCO(2)Et)(dppm)(2)-κ(4) P,C,C′,P′}ClH]Cl·2.75CH(2)Cl(2) and its derivatives, [Ir(III){C(CHCO(2)Et)(dppm)(2)-κ(4) P,C,C′,P′}(CH(2)CO(2)Et)Cl]Cl·CH(3)OH·0.5H(2)O, [Ir(III){C(CHCO(2)Et)(dppm)(2)-κ(4) P,C,C′,P′}Cl(2)]Cl·CH(3)OH·2H(2)O and [Ir(III){C(CHCO(2)Et)(dppm)(2)-κ(4) P,C,C′,P′}(CH(2)CO(2)Et)(CO)]Cl(2)·2CH(2)Cl(2)·1.5H(2)O

The common feature of the four iridium(III) salt complexes, (bis­{[(di­phenyl­phosphan­yl)meth­yl]di­phenyl­phosphanyl­idene}(eth­oxy­oxoethanyl­idene)methane-κ(4) P,C,C′,P′)chlorido­hydridoiridium(III) chloride methyl­ene chloride 2.75-solvate (4), (bis­{[(di­phenyl­phosphan­yl)meth­yl]di­phenyl­phosphanyl­idene}(eth­oxy­oxoethanyl­idene)methane-κ(4) P,C,C′,P′)chlorido­(eth­oxy­oxoethanido)iridium(III) chloride–methanol–water (1/1/0.5) (5), (bis­{[(di­phenyl­phosphan­yl)meth­yl]di­phenyl­phosphanyl­idene}(eth­oxy­oxoethanyl­idene)methane-κ(4) P,C,C′,P′)di­chlorido­iridium(III) chloride–methanol–water (1/1/2) (6) and (bis­{[(di­phenyl­phosphan­yl)meth­yl]di­phenyl­phosphanyl­idene}(eth­oxy­oxoethanyl­idene)methane-κ(4) P,C,C′,P′)carbon­yl(eth­oxy­oxoethanide)iridium(III) dichloride–meth­yl­ene chloride–water (1/2/1.5) (7) or in terms of their formulae [Ir(C(55)H(50)O(2)P(4))ClH]Cl·2.75CH(2)Cl(2) (4), [Ir(C(4)H(7)O(2))(C(55)H(50)O(2)P(4))Cl]Cl·CH(3)OH·0.5H(2)O (5), [Ir(C(55)H(50)O(2)P(4))Cl(2)]Cl·CH(3)OH·2H(2)O (6) and [Ir(C(4)H(7)O(2))(C(55)H(50)O(2)P(4))(CO)]Cl(2)·2CH(2)Cl(2)·1.5H(2)O (7) is a central Ir(III) atom coordin­ated in a distorted octa­hedral fashion by a PCCP ligand system and two additional residues, such as chlorides, a hydride, a carbonyl or an alkyl unit. Thereby, the PCP pincer ligand system and the residue trans to the carbodi­phospho­rane (CDP) C atom surround the iridium(III) transition metal in the equatorial plane under the formation of two five-membered dissimilar chelate rings [C—C(CDP)—P (4, 5, 6 and 7) for the first ring: 120.2 (3), 121.9 (5), 111.2 (3) and 121.7 (2) °; for the second ring: 112.1 (3), 113.5 (5), 120.5 (3) and 108.3 (2)°]. A cyclo­propane-like heterocycle is positioned approximately orthogonal (84.21–88.85°) to the equatorial plane, including an alkyl­idene bridge connecting the Ir(III) atom and the coordinating CDP atom of the PCP subunit. In general, the neutral PCCP ligand system coordinates the metal in a tetra­dentate way via three Lewis acid/base bonds and by an alkyl­idene unit presenting strengthened inter­actions. In all the crystal structures, (disordered) solvent mol­ecules are present in the voids of the packed mol­ecules that inter­act with the positively charged complex and its chloride counter-ion(s) through weak hydrogen bonding.