ㄽᩥᑂᰝࡢせ᪨(Summary of Dissertation Review)༤ኈࡢᑓᨷศ㔝ࡢྡ⛠(Degree)Ꮫ఩ᤵ୚ࡢせ௳༤ ኈ㸦 ⌮Ꮫ 㸧Ꮫ఩つ๎➨ 4 ᮲➨ 1࣭2 㡯ヱᙜẶྡZhang Sihan(Author)ㄽᩥ㢟┠ (Title)
Multinuclear Coinage Metal Complexes of Bis(diphenylphosphinyl)functionalized Dipyrido-annulated N-heterocyclic Carbene(ࣅࢫ(ࢪࣇ࢙ࢽࣝ࣍ࢫࣇ࢕ࢽࣝ)ᐁ⬟ᇶࢆ᭷ࡍࡿࢪࣆࣜࢻ⦰⎔N-࣊ࢸࣟࢧ࢖ࢡࣜࢵࢡ࢝ࣝ࣋ࣥࡢከ᰾㈌ᖯ㔠ᒓ㘒య)ㄽᩥᑂᰝᢸᙜ⪅ (Dissertation Committee)୺  ᰝ(Committee chair)   ຓᩍ SHANG RONG
ᑂᰝጤဨ(Committee member) ᩍᤵ ᒣᮏ 㝧௓                ᑂᰝጤဨ(Committee member) ᩍᤵ Ỉ⏣ ຮᑂᰝጤဨ(Committee member) ᩍᤵ 㰻⸨ ೺୍㸦⮬↛⛉Ꮫ◊✲ᨭ᥼㛤Ⓨࢭࣥࢱ࣮㸧ࠝㄽᩥᑂᰝࡢせ᪨ (Summary of Dissertation Review)ࠞ
1. General Introduction (Chapter 1)
  Phosphine-functionalized N-heterocyclic carbene (NHC) supported multinuclear
coinage metal complexes attract considerable attention owing to their diversestructures, metal-metal interactions and interesting photoluminescence properties.
Generally, two types of ancillary ligands that most are based on the Arduengo typeimidazole scaffold are found in these complexes, namely the phosphine-functionalized
NHC ligands with and without spacers between phosphine and carbene moieties. Thetype A whose carbene and phosphine donors are in proximity usually form
multinuclear complexes with intramolecular metal-metal interactions. Whileoftentimes, the structural diversity is absent in these complexes due to the rigid 2-D
structure and limited rotation along the N-P bond (rotation around one axis only).
The type B allowing the rotation of phosphine arms in all directions form
multinuclearcomplexes

withdiversified

coordinationgeometries.

However,

intramolecular metal-metal interactions which have been proved to affectphotoluminescence properties of resulting complexes usually cannot be found inthese complexes, due to the long distance between carbene and phosphine donors andthe flexibility of the phosphine arms.
  In this context, our group designed and achieved a diphosphine-functionalized
NHC, bis(diphenylphosphinyl)-functionalized dipyrido-annulated NHC (dpaP2-NHC,type C). This ligand features a rigid structure, whose carbene and phosphine donors
are in proximity. More importantly, the characteristic of the phosphine arms rotating
freely around one axis, enables access to different coordination geometries.

2.

Di-- and tetranuclear Au(I) complexes of bis(diphenylphosphinyl)--funcctionalized

dipyrido-annulated NHC (Chapter 2)
  Starting from dpaP2-NHC and its imidazolium salt precursor L(H)I, three
dinuclear and one tetranuclear Au(I) complexes (11-4) have been synthesized andstructurally characterized. Specially, based on interatomic distances in the solid-statestructures, dpaP2-NHC supported gold(I) complexes (22-4) feature intramolecularaurophilic interactions. Complexes 2 and 4 were found to exhibit dynamic behavior insolution judging from NMR spectroscopy, suggesting weak metal-ligand coordination.
All the complexes are fluorescent at room temperature in solution. Moreinterestingly, phosphorescence were observed for all complexes at 77 K with long
lifetimes ranging from 85.1 to 772.0 μs. Complexes 1-4 showed almost sameemissions centered at around 500 nm, which are comparable to that of the carbene
ligand dpaP2-NHC, indicating that the electronic transition of these gold(I) complexes
are mostly attributed to ligand-centered (LC) transitions.
3.

Multinuclear Cu and Ag Complexes of Bis(diphenylphosphinyl)-functionalized

Dipyrido-annulated N-heterocyclic Carbene (Chapter 3)
  A series of homonuclear complexes of dpaP2-NHC have been achieved, including
two dinuclear silver and copper complexes (Ag2L2 and Cu2L2), two tetranuclear coppercomplexes [Cu4L2(NCMe)2 and Cu4LBr4] and a pentanuclear copper complex(Cu5L2Br3). Judging from their NMR spectroscopy, all the complexes show fluxional
behavior in solution, in which, particularly, Ag2L2 underwent a dissociative processaccording to the calculated Erying plot. Interestingly, Cu2L2 contains two carbenes
with different coordination modes, namely a μ-bridging carbene and a terminalcarbene. All the complexes were found to be fluorescent at room temperature insolution. Three homonuclear copper complexes [Cu4L2(NCMe)2, Cu4LBr4 andCu5L2Br3] showed phosphorescence at 77 K. Same as aforementioned gold complexes,
the electronic transitions of these complexes are also mostly attributed to LC
transitions, due to their similar emissions with that of dpaP2-NHC.
  Finally, it is agreed from the above review result that the author of the present
thesis has enough credentials to be awarded the doctoral degree (Science).

බ⾲ㄽᩥ[1] Luminescent Di- and Tetranuclear Gold Complexes of Bis(diphenylphosphinyl)-Functionalized
Dipyrido-Annulated N-Heterocyclic Carbene
S. Zhang, R. Shang, M. Nakamoto, Y. Yamamoto, Y. Adachi and J. Ohshita, Inorg. Chem, 2019, 48,12250-12256[2] Bis(diphenylphosphinyl)-functionalized dipyrido-annulated NHC towards copper(i) and silver(i)S. Zhang, R. Shang, M. Nakamoto, Y. Yamamoto, Y. Adachi and J. Ohshita, Dalton Trans., 2019,58(9), 6328–6335