Syntheses, molecular structures, and self-assemblies of SFe₃, S₂Fe₃, S₃Fe₅, SeFe₃, and Se₂Fe₃ clusters with chelating diaminocarbenes

<div><p>The reactions of substituted thioureas and selenoureas with iron carbonyls have been systematically investigated, and five types of SFe₃, S₂Fe₃, S₃Fe₅, SeFe₃, and Se₂Fe₃ clusters with chelating diaminocarbenes have been synthesized and characterized by X-ray crystallography. The reactions of C₃H₅NHC(=S)NHAr with Fe₃(CO)₁₂ afford (μ₃-S)Fe₃(CO)₇(μ-CO)(κ³<i>C</i>,<i>C</i>,<i>C</i>-C₃H₅NHCNHAr) (<b>1</b>, Ar = Ph; <b>2</b>, Ar = 4-H₂NC₆H₄). In contrast, the reactions of (2-C₅H₄N)NHC(=S)NHN=CHAr with Fe₂(CO)₉ form (μ₃-S)₂Fe₃(CO)₇(κ²<i>N</i>,<i>C</i>-(2-C₅H₄N)NHCNHN=CHAr) (<b>3</b>, Ar = Ph; <b>4</b>, Ar = 4-CH₃C₆H₄). Likewise, reactions of GNHC(=S)NHC(=O)Ph with Fe₃(CO)₁₂ provide (μ₃-S)₂Fe₃(CO)₇(κ²<i>N</i>,<i>C</i>-GNHCNHC(=O)Ph) (<b>5</b>, G = 2-C₅H₄N; <b>6</b>, G = 2-C₄H₃N₂) as well as Fe₃(CO)₈(μ-CO)₂(κ²<i>N</i>,<i>C</i>-(2-C₄H₃N₂)NHCNHC(=O)Ph). The reaction of (2-C₅H₄N)NHC(=S)NH₂ with Fe₃(CO)₁₂ gives (μ₃-S)₂Fe₃(CO)₇(κ²<i>N</i>,<i>C</i>-(2-C₅H₄N)NHCNH₂) (<b>7</b>). The reactions of GNHC(=S)NHPh with Fe₃(CO)₁₂ produce (μ₃-S)₂Fe₃(CO)₇(κ²<i>N</i>,<i>C</i>-GNHCNHPh) (<b>8</b>, G = 2-C₅H₄N; <b>9</b>, G = 2-C₄H₃N₂). Analogously, (2-C₅H₄N)NHC(=S)NH(2-CH₃C₆H₄) offers (μ₃-S)₂Fe₃(CO)₇(κ²<i>N</i>,<i>C</i>-(2-C₅H₄N)NHCNH(2-CH₃C₆H₄)) (<b>10</b>). However, (2-C₅H₄N)NHC(=S)NH(2-CH₃OC₆H₄) generates (μ₃-S)₂(μ₄-S)Fe₅(CO)₁₀(μ-CO)₂(κ²<i>N</i>,<i>C</i>-(2-C₅H₄N)NHCNH(2-CH₃OC₆H₄)) (<b>11</b>). Furthermore, the reactions of (2-C₅H₄N)NHC(=S)NHR with Fe₃(CO)₁₂ form (μ₃-S)₂(μ₄-S)Fe₅(CO)₁₀(μ-CO)₂(κ²<i>N</i>,<i>C</i>-(2-C₅H₄N)NHCNHR) (<b>12</b>, R = 2-H₂NC₆H₄; <b>13</b>, R = 4-H₂NC₆H₄; <b>14</b>, R = 2-C₅H₄N). Surprisingly, the reaction of (2-C₅H₄N)NHC(=S)NHC₃H₅ with Fe₃(CO)₁₂ leads to (μ₃-S)₂(μ₄-S)Fe₅(CO)₁₀(μ-CO)₂(κ²<i>N</i>,<i>C</i>-(2-C₅H₄N)NHCNHC₃H₅) (<b>15</b>). The reaction of C₃H₅NHC(=Se)NHPh with Fe₃(CO)₁₂ affords (μ₃-Se)Fe₃(CO)₇(μ-CO)(κ³<i>C</i>,<i>C</i>,<i>C</i>-C₃H₅NHCNHPh) (<b>16</b>) as well as [(κ²<i>N</i>,<i>C</i>-PhNCNHC₃H₅)Fe₂(CO)₆(μ₄-Se)Fe₂(CO)₆]₂(μ₄-Se). As with (2-C₄H₃N₂)NHC(=S)NHPh, (2-C₄H₃N₂)NHC(=Se)NHPh offers (μ₃-Se)₂Fe₃(CO)₇(κ²<i>N</i>,<i>C</i>-(2-C₄H₃N₂)NHCNHPh) (<b>17</b>). Unlike (2-C₅H₄N)NHC(=S)NH(2-CH₃OC₆H₄), (2-C₅H₄N)NHC(=Se)NH(2-CH₃OC₆H₄) yields (μ₃-Se)₂Fe₃(CO)₇(κ²<i>N</i>,<i>C</i>-(2-C₅H₄N)NHCNH(2-CH₃OC₆H₄)) (<b>18</b>). By virtue of N–HN, N–HO, and C–HO intermolecular hydrogen bonds along with other non-covalent interactions, these new organometallic clusters exhibit interesting supramolecular structures.</p>